Unconjugated cyclopolyene copolymer, rubber composition, and use

ABSTRACT

A tire provided with a tire tread made from a rubber composition comprising 
     (A) a random copolymer based on non-conjugated cyclic polyene comprising structural units originated from one or more α-olefins (A1) and originated from one or more non-conjugated cyclic polyene (A2), the said random copolymer having a content of the structural unit(s) originated from one or more α-olefins (A1) in the range of 93 to 70 mole %; a content of the structural unit originated from one or more non-conjugated cyclic polyene (A2) in the range of 7 to 30 mole %; an intrinsic viscosity [η], determined in decalin at 135° C., in the range of 0.01 to 20 dl/g; a glass transition temperature (Tg) of not higher than 40° C.; and an iodine value in the range of 50 to 150, and 
     (B) a rubber based on diene, 
     in a weight proportion of {the random copolymer based on non-conjugated cyclic polyene (A)} versus {the rubber based on diene (B)} in the range from 60/40 to 0.1/99.9 exhibits a superior braking performance and, compatible therewith, a superior driving fuel cost aspect.

FIELD OF THE INVENTION

The present invention relates to a novel and useful copolymer based onnon non-conjuated cyclic polyene, to a rubber composition containingsuch copolymer and a rubber based on diene and to uses of them.

DESCRIPTION OF THE RELATED TECHNIQUES

There has heretofore been employed in general a rubber compositioncomposed of a styrene/butadiene copolymer rubber (SBR) and naturalrubber for a rubber material for the tread of tires of automobile.However, it has been desired for a tire to have, in addition to highabrasion resistance and lower driving fuel cost concomitant with therecent trend of facilitation of energy economization, a high brakingperformance in respect of the traffic safety. Thus, there is a problemthat conventionally employed product of a blend of styrene/butadienecopolymer rubber and natural rubber does not meet the above requirement.

As a rubber composition which can increase the braking performance andabrasion resistance of tires and can decrease the rolling resistancethereof, a raw rubber blend for tire tread composed of a polybutadienerubber and a halogen-containing polyisobutylene/isoprene rubber isdescribed in Japanese Patent Kokai Sho 56-93738 A. However, also by thisrubber blend, the abrasion resistance, the braking performance and theeffects of reduction in the rolling resistance are not sufficient.

An object of the present invention is to provide a novel and usefulcopolymer based on non-conjugated cyclic polyene capable of servingfavorably as a constituent of rubber material for tires.

Another object of the present invention is to provide a rubbercomposition containing the above copolymer based on non-conjugatedcyclic polyene capable of producing tires exhibiting a superior brakingperformance and a superior driving fuel cost aspect in a compatiblemanner.

A further object of the present invention is to provide a rubbermaterial for tires containing the above copolymer based onnon-conjugated cyclic polyene or the above rubber composition andexhibiting superior properties required for a tire, especially asuperior braking performance and a superior driving fuel cost aspect ina compatible manner.

A still further object of the present invention is to provide a tiretread produced from the above rubber material for tires and to provide atire having such a tire tread.

DISCLOSURE OF THE INVENTION

The present invention consists in the random copolymer based onnon-conjugated cyclic polyene, in the rubber composition and in the usethereof as given in the following:

(1) A random copolymer based on non-conjugated cyclic polyene comprisingstructural units originated from one or more α-olefins (A1) andoriginated from one or more non-conjugated cyclic polyenes (A2), thesaid random copolymer having characteristic features comprising

a content of the structural unit(s) originated from the said one or moreα-olefins (A1) in the range of 93 to 70 mole %,

a content of the structural unit originated from the said one or morenon-conjugated cyclic polyenes (A2) in the range of 7 to 30 mole %,

an intrinsic viscosity [η], determined in Decalin at 135° C., in therange of 0.01 to 20 dl/g,

a glass transition temperature (Tg) of not higher than 40° C. and

an iodine value in the range of 50 to 150.

(2) A random copolymer based on non-conjugated cyclic polyene comprisingstructural units originated from one or more α-olefins (A1), originatedfrom one or more non-conjugated cyclic polyenes (A2) and originated fromone or more non-conjugated linear polyenes (A3), the said randomcopolymer having characteristic features comprising

a content of the structural unit(s) originated from the said one or moreα-olefins (A1) in the range of 97.9 to 55 mole %,

a content of the structural unit originated from the said one or morenon-conjugated cyclic polyenes (A2) in the range of 2 to 30 mole %,

a content of the structural unit originated from the said one or morenon-conjugated linear polyenes (A3) in the range of 0.1 to 15 mole %,

an intrinsic viscosity [η], determined in Decalin at 135° C., in therange of 0.01 to 20 dl/g,

a glass transition temperature (Tg) of not higher than 40° C. and

an iodine value in the range of 5 to 150.

(3) The random copolymer as defined in the above (1) or (2), wherein thestructural unit(s) originated from one or more α-olefins (A1) compriseat least a structural unit originated from ethylene in which the moleratio of (the structural unit originated from ethylene) versus (thestructural unit(s) originated from other α-olefin(s) having 3 or morecarbon atoms) is in the range from 100/0 to 1/99.

(4) The random copolymer as defined in the above (1) or (2), wherein thestructural unit(s) originated from one or more α-olefins (A1) compriseat least a structural unit originated from ethylene in which the moleratio of (the structural unit originated from ethylene) versus (thestructural unit(s) originated from other α-olefin(s) having 3 or morecarbon atoms) is in the range of 100/0 to 50/50.

(5) The random copolymer as defined in any one of the above (1) to (4),wherein the non-conjugated cyclic polyene (A2) is that represented bythe formula (1-1) given below:

 in which m is an integer of 0 to 2, R¹ to R⁴ denote each, independentlyof each other, an atom or a residue selected from the group consistingof hydrogen atom, halogen atoms and hydrocarbon residues which may havedouble bond, wherein R¹ to R⁴ may be fused together to form a mono- orpolycyclic ring which may have double bond or wherein an alkylideneradical may be formed from the pair of R¹ and R² or R³ and R⁴ or,further, R¹ and R³ or R² and R⁴ may be fused together so as to form adouble bond, with the proviso that at least one of R¹ to R⁴ stands foran unsaturated hydrocarbon residue having at least one double bond, incase the mono- or polycyclic ring formed from R¹ to R⁴ by being fusedtogether has no double bond, in case the pair of R¹ and R² or R³ and R⁴does not form an alkylidene radical and in case R¹ and R³ or R² and R⁴are not fused together to form an endocyclic double bond.

(6) The random copolymer as defined in any one of the above (2) to (5),wherein the non-conjugated linear polyene (A3) is represented by theformula (2-1) given below:

 in which p and q is zero or 1 with the proviso that p and q are notzero simultaneously, f is an integer of zero to 5 with the proviso thatf is not zero when both p and q are 1, g is an integer of 1 to 6, R¹,R², R³, R⁴, R⁵, R⁶ and R⁷ denote each, independently of each other,hydrogen atom or an alkyl group having 1-3 carbon atoms, R⁸ denoted analkyl group having 1-3 carbon atoms and R⁹ denotes hydrogen atom, analkyl group having 1-3 carbon atoms or a group represented by—(CH₂)n-CR¹⁰═C(R¹¹)R¹² in which n is an integer of 1 to 5, R¹⁰ and R¹¹represent each, independently of each other, hydrogen atom or an alkylgroup having 1-3 carbon atoms and R¹² represents an alkyl group having1-3 carbon atoms, with the proviso that R⁹ is hydrogen atom or an alkylgroup having 1-3 carbon atoms when both p and q are 1.

(7) A rubber composition comprising

(A) a random copolymer based on non-conjugated cyclic polyene comprisingstructural units originated from one or more α-olefins (A1) andoriginated from one or more non-conjugated cyclic polyenes (A2), thesaid random copolymer having characteristic features comprising acontent of the structural unit(s) originated from the said one or moreα-olefins (A1) in the range of 93 to 70 mole %; a content of thestructural unit originated from the said one or more non-conjugatedcyclic polyenes (A2) in the range of 7 to 30 mole %; an intrinsicviscosity [η], determined in Decalin at 135° C., in the range of 0.01 to20 dl/g; a glass transition temperature (Tg) of not higher than 40° C.;and an iodine value in the range of 50 to 150, and

(B) a rubber based on diene,

wherein the weight proportion of (the random copolymer based onnon-conjugated cyclic polyene) versus (the rubber based on diene),namely, (A/(B), is in the range of 60/40 to 0.1/99.9.

(8) A rubber composition comprising

(A) a random copolymer based on non-conjugated cyclic polyene comprisingstructural units originated from one or more α-olefins (A1), originatedfrom one or more non-conjugated cyclic polyenes (A2) and originated fromone or more non-conjugated linear polyenes (A3), the said randomcopolymer having characteristic features comprising a content of thestructural unit(s) originated from the said one or more α-olefins (A1)in the range of 97.9 to 55 mole %; a content of the structural unitoriginated from the said one or more non-conjugated cyclic polyenes (A2)in the range of 2 to 30 mole %; a content of the structural unitoriginated from the said one or more non-conjugated linear polyenes (A3)in the range of 0.1 to 15 mole %; an intrinsic viscosity [η], determinedin Decalin at 135° C., in the range of 0.01 to 20 dl/g; a glasstransition temperature (Tg) of not higher than 40° C.; and an iodinevalue in the range of 5 to 150, and

(B) a rubber based on diene,

wherein the weight proportion of (the random copolymer based onnon-conjugated cyclic polyene) versus (the rubber based on diene),namely, (A/(B), is in the range of 60/40 to 0.1/99.9.

(9) The rubber composition as defined in the above (7) or (8) whereinthe structural unit(s) originated from one or more α-olefins (A1) in therandom copolymer based on non-conjugated cyclic polyene comprise atleast a structural unit originated from ethylene, wherein the mole ratioof (the structural unit originated from ethylene) versus (the structuralunit(s) originated from other α-olefin(s) having 3 or more carbon atoms)is in the range of 100/0 to 1/99.

(10) The rubber composition as defined in the above (7) or (8) whereinthe structural unit(s) originated from one or more α-olefins (A1) in therandom copolymer based on non-conjugated cyclic polyene comprise atleast a structural unit originated from ethylene, wherein the mole ratioof (the structural unit originated from ethylene) versus (the structuralunit(s) originated from other α-olefin(s) having 3 or more carbon atoms)is in the range of 100/0 to 50/50.

(11) The rubber composition as defined in any one of the above (7) to(10), wherein the non-conjugated cyclic polyene (A2) is that representedby the formula (1-1).

(12) The rubber composition as defined in any one of the above (8) to(11), wherein the non-conjugated linear polyene (A3) is that representedby the formula (2-1).

(13) A rubber material for tires, comprising the random copolymer basedon non-conjugated cyclic polyene as difined in any one of the above (1)to (6).

(14) A rubber material for tires, comprising the rubber composition asdifined in any one of the above (7) to (12).

(15) A tire tread produced from the rubber material for tires as definedin the above (13) or (14).

(16) A tire which has a tire tread as defined in the above (15).

The copolymer based on non-conjugated cyclic polyene to be incorporatedaccording to the present invention is a random copolymer comprisingstructural unit(s) originated from one or more α-olefins (A1) and astructural unit originated from one or more non-conjugated cyclicpolyenes (A2) and has characteristic features comprising a content ofthe structural unit(s) of the α-olefin(s) (A1) in the range from 93 to70 mole %, preferably from 93 to 75 mole %, more preferably from 93 to80 mole %, a content of the structural unit of the non-conjugated cyclicpolyene (A2) in the range from 7 to 30 mole %, preferably from 7 to 25mole %, more preferably from 7 to 20 mole %, an intrinsic viscosity[72T], determined in Decalin (decahydronaphthalene) at 135° C., in therange from 0.01 to 20 dl/g, preferably from 0.1 to 10 dl/g, morepreferably from 0.5 to 5 dl/g, a glass transition temperature (Tg) ofnot higher than 40° C., preferably in the range from −30° C. to +20° C.,more preferably from −30° C. to +15° C., most preferably from −30 to+10° C., and an iodine value in the range from 35 to 150, preferablyfrom 35 to 130, more preferably from 35 to 120.

The copolymer based on non-conjugated cyclic polyene to be incorporatedaccording to the present invention may also be a random copolymercomprising structural unit(s) originated from one or more α-olefins (A1)and structural units originated from a non-conjugated cyclic polyene(A2) and originated from one or more non-conjugated linear polyenes (A3)and has characteristic features comprising a content of the structuralunit(s) originated from the α-olefin(s) (A1) in the range from 97.9 to55 mole %, preferably from 97 to 70 mole %, more preferably from 97 to80 mole %, a content of the structural unit originated from thenonconjugated cyclic polyene (A2) in the range from 2 to 30 mole %,preferably from 2.5 to 25 mole %, more preferably from 2.5 to 15 mole %,a content of the structural unit(s) originated from the non-conjugatedlinear polyene(s) (A3) in the range from 0.1 to 15 mole %, preferablyfrom 0.5 to 10 mole %, more preferably from 0.5 to 5 mole %, anintrinsic viscosity [η], determined in Decalin (decahydronaphthalene) at135° C., in the range from 0.01 to 20 dl/g, preferably from 0.01 to 10dl/g, more preferably from 0.5 to 5 dl/g, a glass transition temperature(Tg) of not higher than 40° C., preferably in the range from −30° C. to+20° C., more preferably from −30° C. to +10° C., and an iodine value inthe range from 5 to 150, preferably from 10 to 130, more preferably from10 to 120.

The glass transition temperature (Tg) can be determined by a dynamicrheological testing method from the peak on the damping factor in theobservation of the temperature dispersion.

Due to the above characteristic features with respect to the contents ofthe structural units originated from the α-olefin(s) (A1) and originatedfrom the non-conjugated cyclic polyene(s) (A2) or the contents of thestructural units of originated from the α-olefin(s) (A1), originatedfrom the non-conjugated cyclic polynene (A2) and originated from thenon-conjugated linear polyene(s) (A3), the glass transition temperature(Tg) and the iodine value, the random copolymer based on non-conjugatedcyclic polyene according to the present invention can afford, when usedsolely or in combination with a rubber based on diene (B), which will bedescribed afterwards, to obtain tires with treads exhibiting an improvedbraking performance due to increased grasping or clinging action ontothe traffic road face with simultaneous attainment of a compatibilitywith an improvement of the driving fuel cost due to reduction of rollingresistance during steady running, wherein the balance between theabove-mentioned characteristic features will be more superior if thevalues of these features are in the above preferable ranges and furtherin the more preferable ranges.

Due to the intrinsic viscosity held in the above-defined range, therandom copolymer based on non-conjugated cyclic polyene according to thepresent invention is superior in the mechanical strength and in theworkability, wherein the closer the intrinsic viscosity value to theabove-mentioned preferable range and further to the above-mentioned morepreferable range, the more superior these properties will be.

When the random copolymer based on non-conjugated cyclic polyeneaccording to the present invention is used as a constituent of therubber material for tires, its crystallinity should preferably be lower.

As the α-olefins (A1) constituting the random copolymer based onnon-conjugated cyclic polyene according to the present invention, theremay be used those having 2-20 carbon atoms, preferably 3-15 carbonatoms, such as, ethylene, 1-butene, 1-hexene, 1-octene, 1-decene,1-dodecene and 4-methyl-1-pentene. These α-olefins (A1) may be usedeither solely or in a combination of two or more of them.

The random copolymer based on non-conjugated cyclic polyene according tothe present invention may favorably contain, as the structural unit(s)originated from one or more α-olefins (A1), at least a structural unitoriginated from ethylene, wherein the mole ratio of the structural unitoriginated from ethylene versus the structural unit(s) originated fromother α-olefin(s) having 3 or more carbon atoms may be in the range from100/0 to 1/99, preferably from 100/0 to 50/50, more preferably from 95/5to 50/50.

For the non-conjugated cyclic polyene (A2) constituting the randomcopolymer based on non-conjugated cyclic polyene to be incorporatedaccording to the present invention, every cyclic compound having two ormore non-conjugated unsaturation bonds can be employed without anyrestriction, wherein preference is given to non-conjugate cyclicpolyenes represented by the above formula (1-1).

As the halogen atom denoted by R¹ to R⁴ in the non-conjugated cyclicpolyene (A2) represented by the above formula (1-1), there may beexemplified fluorine atom, chlorine atom, bromine atom and iodine atom.

As the hydrocarbon residues denoted by R¹ to R⁴ in the above formula(1-1), there may be enumerated, for example, alkyls having 1 to 20carbon atoms, halogenated alkyls having 1 to 20 carbon atoms,cycloalkyls having 3 to 15 carbon atoms, aroamtic hydrocarbon residueshaving 6 to 20 carbon atoms and unsaturated hydrocarbon residues havingat least one double bond. More concretely, as the alkyls, there may beexemplified methyl, ethyl, propyl, isopropyl, amyl, hexyl, octyl, decyl,dodecyl and octadecyl. As the halogenated alkyl, there may beexemplified those in which at least a part of the hydrogen atoms in thealkyls mentioned above is replaced by a halogen atom, such as fluorine,chlorine, bromine or iodine. As the cycloalkyls, there may beexemplified cyclohexyl and the like. As the aroamtic hydrocarbonresidues, there may be exemplified phenyl and naphthyl. As theunsaturated hydrocarbon residues, there may be exemplified vinyl andallyl.

In the formula (1-1), the pairs of R¹ and R², R³ and R⁴, R¹ and R³, R²and R⁴, R¹ and R⁴ as well as R² and R³ may form each a mono- orpolycyclic ring by combining each other (under cooperation), whereinsuch mono- or polycyclic ring may have double bond(s).

It is also possible that the pair R¹ and R² or R³ and R⁴ in the formula(1-1) may form together an alkylidene radical. Such an alkylideneradical may usually be that having 1 to 20 carbon atoms, with concreteexamples including methylene (CH₂═), ethylidene (CH₃CH═), propylidene(CH₃CH₂CH═) and isopropylidene {(CH₃)₂C═}.

Concrete examples of the non-conjugated cyclic polyene (A2) representedby the formula (1-1) include alkylidene-containing ones (A2-1) whichhave each an alkylidene radical formed from the pair of R¹ and R² or R³and R⁴, polycyclic ones (A2-2) in which a mono- or polycyclic ringhaving at least one double bond is formed from R¹ to R⁴ by combiningeach other, unsaturated hydrocarbon residue-containing ones (A2-3) inwhich at least one of R¹ to R⁴ is a monovalent unsaturated hydrocarbonresidue having one or more double bonds and ring-symmetrical ones (A2-4)in which either R¹ and R³ or R² and R⁴ are fused to form a double bondso that the resulting cyclic polyene has a geometric symmetry withrespect to the straight line connecting the bridgehead carbon atoms orthe commonly shared carbon atoms of the condenced ring with each otheras the axis of symmetry.

Concrete examples of the alkylidene-containing non-conjugated cyclicpolyene (A2-1) include those which are represented by the followingformula (1-2)

in which s stands for an integer of 0 to 2, R¹⁷ denotes an alkylideneradical, R¹⁸ and R¹⁹ denote each, independently of each other, an atomor a residue selected from the group consisting of hydrogen atom,halogen atoms and hydrocarbon residues, wherein R¹⁸ and R¹⁹ may formtogether an alkylidene radical.

As the concrete examples of the alkylidene radicals denoted by R¹⁷ inthe formula (1-2), those which have 1-20 carbon atoms, such asmethylene, ethylidene, propylidene and isopropylidene, may be recited.

The symbol s in the formula (1-2) may preferably stands for zero. As thehalogen atom denoted by R¹⁸ and R¹⁹, those exemplified previously arerecited. As the hydrocarbon residues, alkyls having 1 to 20 carbonatoms, halogenated alkyls having 1 to 20 carbon atoms, cycloalkylshaving 3 to 15 carbon atoms and aromatic hydrocarbon residues having6-20 carbon atoms may be recited.

As concrete examples of the alkylidene-containing non-conjugated cyclicpolyene (A2-1) represented by the formula (1-2), there may be enumerated5-methylene-2-norbornene, 5-ethylidene-2-norbornene (ENB) and5-isopropylidene-2-norbornene as well as the compounds given below.Among them, preference is given to 5-ethylidene-2-norbornene.

Concrete examples of the above-mentioned non-conjugated polycyclicpolyene (A2-2) include dicyclopentadiene (DCPD),dimethyldicyclopentadiene and the compounds given below.

As concrete examples of the above-mentioned unsaturated hydrocarbonresidue-containing non-conjugated cyclic polyene (A2-3), there may beenumerated 5-vinyl-2-norbornene and the compounds given below.

As concrete examples of the above-mentioned ring-symmetricalnon-conjugated cyclic polyene (A2-4), the compounds given bolow may berecited.

For the non-conjugated cyclic polyene (A2) represented by the formula(1-1), those in which m stands for zero are preferred, wherein specialpreference is given to the alkylidene group-containing non-conjugatedcyclic polyenes (A2-1) in which m in the formula (1-1) stands for zero,namely, those in which s in the formula (1-2) stands for zero, and tothe polycyclic non-conjugated cyclopolyenes (A2-2) in which m in theformula (1-1) stands for zero. Most preferred ones among them are thealkylidene group-containing non-conjugated cyclic polyenes (A2-1) inwhich s in the formula (1-2) stands for zero, wherein, concretely,5-ethylidene-2-norbornene (ENB) is most preferable.

The non-conjugated linear polyene (A-3) constituting the copolymer basedon non-conjugated cyclic polyene according to the present invention is acompound having in the molecule two or more non-conjugated unsaturationbonds, for which non-conjugated dienes, non-conjugated trienes,non-conjugated tetraenes and the like may be employed. Thenon-conjugated linear polyene (A3) may be used either alone or in acombination of two or more thereof.

As the non-conjugated linear polyene (A3), non-conjugated trienes andtetraenes (A3-1) represented by the formula (2-1) given above, aboveall, non-conjugated trienes (A3-2) represented by the formula (2-2)given below are favorable in view of the balance between the brakingperformance and the fuel cost aspect, vulcanization feature, processingperformance on the vulcanization (scorching stability) and so on.

in which R¹ to R⁵ denote each, independently of each other, hydrogenatom, methyl group or ethyl group, with the proviso that R⁴ and R⁵ donot stand for hydrogen atom simultaneously.

The non-conjugated trienes (A3-2) represented by the formula (2-2)correspond to the non-conjugated trienes or tetraenes (A3-1) representedby the formula (2-1) in which f is zero, g is 2, p is zero, q is 1 andR⁵ and R⁶ stand both for hydrogen atom. Among the non-conjugated trienes(A3-2) represented by the formula (2-2), those in which both R³ and R⁵stand for methyl group are preferred, wherein the copolymer based onnon-conjugated cyclic polyene according to the present inventionobtained using such non-conjugated triene (A3-2) as the comonomer can beused for the rubber composition which will be described afterwards andfrom which tires superior especially in the braking performance and,compatible therewith, in the fuel cost aspect can be produced.

Concrete examples of the non-conjugated linear polyene (A3) include1,4-hexadiene, 1,3-butadiene, isoprene, 7-methyl-1,6-octadiene,6-methyl-1,6-octadiene, 6,7-dimethyl-1,6-octadiene,7-methyl-1,6-decadiene, 6-methyl-1,6-nonadiene,6,7-dimethyl-1,6-nonadiene, 7-methyl-1,6-nonadiene and6-methyl-1,6-decadiene.

As the non-conjugated trienes and tetraenes (A3-1) represented by theformula (2-1), concretely compounds such as those given below (excludingthose falling under the definition represented by the formula (2-2)) maybe exemplified:

Among the above non-conjugated trienes and tetraenes (A3-1), the firstgiven 4-ethylidene-8-methyl-1,7-nonadiene (abbreviated in the followingsometimes as EMND) is favorable from the point of view of the brakingperformance and driving fuel cost aspect attained therewith.

Concrete examples of the non-conjugated trienes (A3-2) represented bythe formula (2-2) include:

Among the above non-conjugated trienes (A3-2), the first given4,8-dimethyl-1,4,8-decatriene (in the following, abbreviated sometimesas DMDT) is preferred.

The non-conjugated polyenes represented by the formulae (2-1) and (2-2)take usually geometrical isomeric structures (trans- and cis-isomers).The non-conjugated polyene (A3) to be used as a comonomer according tothe present invention may be a mixture of the trans- and cis-isomers orcomposed solely of either one of the isomers.

The non-conjugated trienes and tetraenes (A3-1) represented by theformula (2-1) may be produced by a process known per se. For example,the non-conjugated trienes and tetraenes of the formula (2-1) in which pis zero and q stands for 1 can be produced as follows. First, a Grignardreagent (an allyl-MgX or vinyl-MgX) is prepared by reacting a vinylgroup-containing halide (such as an allyl halide or a vinyl halide) withmetallic magnesium. Then, by reacting a halide of a non-conjugateddouble bond-containing linear hydrocarbon (such as geranyl halide) withthe above Grignard reagent, the non-conjugated triene or tetraene (A3-1)represented by the formula (2-1) is formed by radical reaction. Also,the non-conjugated triene or tetraene represented by the formula (2-1)in which p stands for 1 and q is zero can be produced by reacting aconjugated diene represented by the following formula (2-3) or (2-4)with ethylene. Concrete process of the production is described in detailin Japanese Patent Kokai A Hei 9-235327 (corresponding to U.S. Pat. No.5,744,566) filed by the applicant.

In the above formulae (2-3) and (2-4), f, g, R¹, R² and R⁵ to R⁹ havethe same meanings as in the formula (2-1).

The non-conjugated triene (A3-2) represented by the formula (2-2) can beproduced by reacting a triene compound having conjugated diene structure(denoted hereinafter as the triene having conjugated diene structure)represented by the formula (2-5) with ethylene.

in which R¹, R², R³, R⁴ and R⁵ have the same meanings as in the formula(2-2).

The reaction of the triene compound having conjugated diene structurerepresented by the formula (2-5) with ethylene may favorably be carriedout at a temperature usually in the range from 30 to 200° C., preferablyfrom 50 to 150° C., under an ethylene pressure usually in the range from0.05 to 9.8 MPa (from 0.5 to 100 kgf/cm², gauge), preferably from 0.2 to6.9 MPa (from 2 to 70 kgf/cm², gauge), for a reaction duration usuallyin the range from 0.5 to 30 hours. The reaction may be performed underan atmosphere of ethylene gas per se or an atmosphere of ethylene gascontaining an inert gas, such as nitrogen or argon. While a reactionsolvent is not particularly necessary, use thereof may be permitted. Asthe reaction solvent, there may favorably be used, for example,hydrocarbon solvent, such as hexane, heptane, octane, nonane, decane,undecane, tridecane, toluene and xylene.

The reaction of the triene compound having conjugated diene structurerepresented by the formula (2-5) with ethylene is carried out usually inthe presence of a catalyst. As the catalyst, for example, a catalystmade of a transition metal thiocyanate, one or more organic compoundscapable of coordinating to the transition metal atom of the thiocyanateas ligand and an organoaluminum compound may be employed.

As the transition metal thiocyanate, there may be enumerated concretelythiocyanates of elements of Group 8 of the periodic table (that given byGroups of 1 to 18), such as iron and ruthenium; of Group 9 thereof, suchas cobalt, rhodium and iridium; and of Group 10 thereof, such as nickeland palladium.

For the organic compound capable of coordinating to the tansition metalas ligand, there may be recited, for example, phosphorus-containingcompounds, such as tri-o-tolylphosphine, triethylphosphine,tripropylphosphine, tributylphosphine, triphenylphosphine,bis(diphenylphosphino)methane, 1,2-bis(diphenylphosphino)ethane,1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane,triphenyl phosphite, triphenylphosphine oxide and triphenyl phosphate.

As the organoaluminum compound, there may be recited, for example,trimethylaluminum, triethylaluminum, triisobutylaluminum,dimethylaluminum chloride, diethylaluminum chloride, ethylaluminumdichloride and diethylaluminum ethoxide.

The random copolymer based on non-conjugated cyclic polyene according tothe present invention can be produced by co-polymerizing an α-olefin(A1) and a non-conjugated cyclic polyene (A2), such as that representedby the formula (1-1), or by co-polymerizing an α-olefin (A1) with anon-conjugated cyclic polyene (A2), such as that represented by theformula (1-1), and a non-conjugated linear polyene (A3), such as thatrepresented by the formula (2-1) in the presence of a catalyst. As thecatalyst, those which are composed of a transition metal compound (C),such as a compound of vanadium (V), zirconium (Zr) or titanium (Ti), andan organoaluminum compound or an organoaluminum-oxy compound (D) and/oran ionizing ionic compound (E) may be employed.

Concrete examples of the catalyst include

(1) a catalyst based on vanadium made of a soluble vanadium compound(c-1) and an organoaluminum compound (d-1) and

(2) a catalyst based on metallocene composed of a metallocene (c-2) of atransition metal selected from the group consisting of metals of Group 4of the periodic table of elements of 18 groups (which applies to all thecases in the following), an organoaluminum-oxy compound (d-2) and/or anionizing ionic compound (e-1).

For the soluble vanadium compound (c-1) constituting the catalyst basedon vanadium, compounds represented by the formulae (3) and (4) givenbelow may be recited.

VO(OR)_(a)X_(b)  (3)

V(OR)_(c)X_(d)  (4)

in which R denotes a hydrocarbon residue, X denotes a halogen atom anda, b, c and d satisfies the following conditions:

0≦a≦3, 0≦b≦3, 2≦a+b≦3, 0≦c≦4, 0≦d≦4 and 3≦c+d≦4

As the soluble vanadium compound (c-1), electron donor-added products ofsoluble vanadium compounds obtained by contacting with an electron donormay also be employed.

As the organoaluminum compound (d-1) for building up the catalyst basedon vanadium, those in which at least one Al—C bond is included in themolecule can be employed. Examples of such a compound includeorganoaluminum compounds exemplified by the following formula (5)

(R¹)_(m)Al(OR²)_(n)H_(p)X_(q)  (5)

in which R¹ and R² represent each a hydrocarbon residue which may beidentical with or different from each other and which has ordinarily 1to 15 carbon atoms, preferably 1 to 4 carbon atoms, X denotes a halogenatom and m, n, p and q stand each for a numeral which mees theconditions 0<m≦3, 0≦n<3, 0≦p<3, and 0≦q<3, with m+n+p+q=3.

The metallocene (c-2) constituting the catalyst based on metallocene isthat of a metal selected from the transition metals of Group 4 of theperiodic table and is, concretely, one expressed by the followingformula (7)

ML_(x)  (7)

in which M denotes a transition metal selected from the Group 4 of theperiodic table, x is the valence of the transition metal M and Lrepresents a ligand.

Concrete examples of the transition metal in the formula (7) representedby the symbol M include zirconium, titanium and hafnium. The ligands Lin the formula (7) coordinate to the transition metal M, wherein atleast one of these ligands L has a cyclopentadienyl skeleton. Thisligand having cyclopentadienyl skeleton may have substitutent(s).

Concrete examples of the ligand L having cyclopentadienyl skeletoninclude such groups as alkyl- or cycloalkyl-substitutedcyclopentadienyl, such as, cyclopentadienyl, methylcyclopentadienyl,ethylcyclopentadienyl, n- and i-propylcyclopentadienyls, n-, i-, sec-and tert-butylcyclopentadienyls, dimethylcyclopentadienyl,methylpropylcyclopentadienyl, methylbutylcyclopentadienyl andmethylbenzylcyclopentadienyl; and others, such as indenyl,4,5,6,7-tetrahydroindenyl and fluorenyl.

These ligand groups having cyclopentadienyl skeleton may further besubstituted by, for example, halogen atom(s) and trialkylsilyl group(s).

In case where the compound represented by the formula (7) has two ormore groups having cyclopentadienyl skeleton as ligand L, two of thesegroups having cyclopentadienyl skeleton may be bound together through abridging group, for example, an alkylene, such as ethylene or propylene;a substituted alkylene, such as isopropylidene or diphenylmethylene;silylene; or a substituted silylene, such as dimethylsilylene,diphenylsilylene or methylphenylsilylene.

For other ligands L than those having the cyclopentadienyl skeleton,namely, ligands without cyclopentadienyl skeleton, there may beenumerated, for example, hydrocarbon groups, alkoxy groups, aryloxygroups and sulfo-containing groups (—SO₃R^(a), in which R^(a) denotes analkyl, a halogen-substituted alkyl, an aryl or a halogen- oralkyl-substituted aryl), which have 1-12 carbon atoms, as well ashalogen atoms and hydrogen atom.

As the hydrocarbon groups having 1-12 carbon atoms for the ligand L,there may be enumerated such groups as alkyl, cycloalkyl, aryl andaralkyl and, more concretely, alkyl groups, such as methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl,hexyl, octyl, decyl and dodecyl; cycloalkyl groups, such as cyclopentyland cyclohexyl; aryl groups, such as phenyl and tolyl; and aralkylgroups, such as benzyl and neophyl.

As the alkoxy group for the ligand L, there may be enumerated, forexample, methoxy, ethoxy and n-propoxy. As the aryloxy group, forexample, phenoxy may be enumerated. As the sulfo-containing group (—SO₃^(a)), there may be enumerated, for example, methanesulfonato,p-toluenesulfonato, trifluoromethanesulfonato andp-chlorobenzenesulfonato. As the halogen atom, fluorine, chlorine,bromine and iodine are exemplified.

When the transition metal of the metallocene represented by the formula(7) has a valency of 4, it may be represented more concretely by theformula (8):

R² _(k)R³ _(l)R⁴ _(m)R⁵ _(n)M  (8)

in which M is a transition metal same as that given in the formula (7),R² represents a group (ligand) having cyclopentadienyl skeleton, R³, R⁴and R⁵ represent each, independently of each other, a group (ligand)with or without cyclopentadienyl skeleton and k is an integer of 1 orhigher, wherein k+1+m+n=4.

Examples of the metallocene (c-2) in which M is zirconium and whichcontains at least two ligands having each a cyclopentadienyl skeletonare given below:

Bis(cyclopentadienyl)zirconium monochloride monohidride,

bis(cyclopentadienyl)zirconium dichloride,

bis(1-methyl-3-butylcyclopentadienyl)zirconium dichloride and

bis(1,3-dimethylcyclopentadienyl)zirconium dichloride.

It is also possible to use a compound in which the 1,3-substitutedcyclopentadienyl as given above is replaced by a corresponding1,2-substituted cyclopentadienyl.

There may also be exemplified metallocenes (c-2) of bridged structure inwhich, in the above formula (8), at least two of the ligands R², R³, R⁴and R⁵, for example, R² and R³ are the group (ligand) havingcyclopentadienyl skeleton and such at least two groups are bound eachother through, for example, alkylene, substituted alkylene, silylene orsubstituted silylene. In this case, the groups R⁴ and R⁵ stand,independently of each other, for the ligand L other than that havingcyclopentadienyl skeleton as explained in the formula (7).

As the metallocene (C-2) of such a bridged structure, there may beenumerated, for example,

ethylenebis(indenyl)dimethylzirconium,

ethylenebis(indenyl)zirconium dichloride,

isopropylidenebis(1-indenyl)zirconium dichloride,

isopropylidene(cyclopentadienyl-fluorenyl)zirconium dichloride,

diphenylsilylenebis(indenyl)zirconium dichloride,

methylphenylsilylenebis(indenyl)zirconium dichloride,

rac-ethylene(2-methyl-1-indenyl)2-zirconium dichloride,

rac-dimethylsilylene(2-methyl-1-indenyl)2-zirconium dichloride,

rac-dimethylsilylene-bis(4-phenyl-1-indenyl)zirconium dichloride,

rac-dimethylsilylene-bis(2-methyl-4-phenyl-1-indenyl)zirconiumdichloride,

rac-dimethylsilylene-bis(2-methyl-4-(α-naphthyl)-1-indenyl)zirconiumdichloride,

rac-dimethylsilylene-bis{2-methyl-4-(β-naphthyl)-1-indenyl}zirconiumdichloride,

rac-dimethylsilylene-bis{2-methyl-4-(1-anthracenyl)-1-indenyl}zirconiumdichloride and

diphenylmethylene(cyclopentadienyl-9-fluorenyl)zirconium dichloride.

It is also possible to use transition metal compounds in which zirconiumof the above-recited compounds is replaced by titanium or by hafnium.

It is also possible to use compounds represented by the formula (9)given below, as the compound (c-2).

L^(a)MX_(z)  (9)

in which M is a metal of Group 4 or of the lanthanide series of theperiodic table, L^(a) denotes a derivative of non-localized π-bondinggroup, which provides the active site of the metal M with a captivegeometry, and the two Xs represent each, independently of each other,hydrogen atom, a halogen atom, a hydrocarbon group having 20 or lesscarbon atoms, a silyl group having 20 or less silicium atoms or a germylgroup having 20 or less germanium atoms.

Among these compounds represented by the formula (9), preference isgiven to those expressed by the following formula (10):

in which M is titanium, zirconium or hafnium, X has the same meaning asthat of the formula (9), Cp denotes a substituted cyclopentadienyl groupsubstituted by Z and bound to M by π-bonding, Z represents oxygen atom,sulfur atom, boron atom or an element of Group 4 of the periodic table,such as silicium, germanium or tin, and Y is a ligand containingnitrogen, phosphorus, oxygen or sulfur, wherein Z and Y may build uptogether a condensed ring.

Concrete examples of the compounds represented by the formula (10)include(t-butylamido)dimethyl(tetramethyl-η⁵-cyclopentadienyl)silanetitaniumdichloride,{(t-butylamido)(tetramethyl-η⁵-cyclopentadienyl)-1,2-ethanediyl}titaniumdichloride and the like.

It is also possible to use compounds in which titanium of the abovemetallocenes is replaced by zirconium or hafnium.

For the metallocenes (c-2) represented by the formulae (9) or (10),zirconocenes in which the central metal atom is zirconium and which haveat least two cyclopentadienyl skeletons may favorably be used.

Now, the description is directed to the organic aluminum oxy-compound(d-2) and to the ionizing ionic compound (e-1) to be used for preparingthe metallocene catalyst.

As the organic aluminum-oxy compound (d-2), known aluminoxanes and thosebenzene-insoluble organic aluminum-oxy compounds (d-2) may be used.

Concretely, these known aluminoxanes are represented by the followingformulae (11) and (12):

In the above formulae (11) and (12), R is a hydrocarbon group, such asmethyl, ethyl, propyl or butyl, wherein preference is given for methyland ethyl, especially for methyl, and m is an integer of 2 or greater,preferably of 5-40.

The aluminoxane of the formula (11) or (12) may be constituted of mixedalkyloxyaluminum units composed of an alkyloxyaluminum unit representedby the formula {OAl(R¹)} and of an alkyloxyaluminum unit represented bythe formula {OAl(R²)}, wherein R¹ and R² are each a hydrocarbyl groupsimilar to that of R but are different from each other.

A content of small amount of organometallic compound(s) of othermetal(s) than aluminum in addition to the organoaluminum-oxy compound(d-2) may be permissible.

For the ionizing ionic compound (e-1), which may sometimes be denoted asionic ionizing compound or ionic compound, there may be exemplifiedLewis acids, ionic compounds, boranes and carboranes.

For such a Lewis acid, compounds represented by the formula BR₃ (R maystand for fluorine or a phenyl group which may have substituentgroup(s), such as fluorine, methyl and trifluoromethyl) may bementioned. Concrete example of the Lewis acid include trifluoroboron,triphenylboron, tris(4-fluorophenyl)boron,tris(3,5-difluorophenyl)boron, tris(4-fluoromethylphenyl)boron,tris(pentafluorophenyl)boron, tris(p-tolyl)boron, tris(o-tolyl)boron andtris(3,5-dimethylphenyl)boron.

As the ionic compounds, there may be enumerated, for example,trialkyl-substituted ammonium salts, N,N-dialkylanilinium salts,dialkylammonium salts and triarylphosphonium salts. For thetrialkyl-substituted ammonium salt as the ionic compound, there may beenumerated, for example, triethylammonium tetra(phenyl)borate,tripropylammonium tetra(phenyl)borate and tri(n-butyl)ammoniumtetra(phenyl)borate. For the dialkylammonium salt as the ionic compound,there may be enumerated, for example, di(1-propyl)ammoniumtetra(pentafluorophenyl)borate and dicyclohexylammoniumtetra(phenyl)borate.

As the ionic compound, there may further be enumeratedtriphenylcarbenium tetrakis(pentafluorophenyl)borate,N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate and ferroceniumtetra(pentafluorophenyl)borate.

As the borane compound mentioned above, there may be enumerateddecaborane(9); salts of metalborane anions, for example,bis[tri(n-butyl)ammonium]nonaborate, bis[tri(n-butyl)ammonium]decaborateandbis[tri(n-butyl)ammonium]bis(dodecahydridododecaborate)nickelate(III).

As the carboranes mentioned above, there may be enumerated, for example,salts of metalcarborane anions, such as 4-carbanonaborane(9),1,3-dicarbanonaborane(8) andbis[tri(n-butyl)ammonium]bis(undecahydrido-7-carba-undecaborate)nickelate(IV).

These ionizing ionic compounds (e-1) may be used alone or in acombination of two or more of them.

For preparing the catalyst based on metallocene, it is possible toincorporate the above-mentioned organoaluminum compound (d-1) inaddition to the organoaluminum-oxy compound (d-2) or the ionizing ioniccompound (e-1).

For producing the copolymer based on non-conjugated cyclic polyeneaccording to the present invention, the α-olefin (A1) and thenon-conjugated cyclic polyene (A2) or the α-olefin (A1), thenon-conjugated cyclic polyene (A2) and the non-conjugated linear polyene(A3) are subjected to copolymerization usually in liquid phase in thepresence of the catalyst based on vanadium or metallocene as describedabove. Here, a hydrocarbon solvent is used in general, while thesecomonomers may be used as the solvent.

The copolymerization may be carried out in a batchwise or continuousway. On carrying out the copolymerization in batchwise way, the catalystis used at a concentration as given below.

When a vanadium-based catalyst composed of the soluble vanadium compound(c-1) and the organoaluminum compound (d-1) is used, the concentrationof the soluble vanadium compound in the polymerization system mayusually be in the range from 0.01 to 5 mmol/liter (polymerizationvolume), preferably from 0.05 to 3 mmol/liter. The soluble vanadiumcompound (c-1) may favorably be supplied thereto at a concentration ofat most ten times, preferably 1-7 times, more preferably 1-5 times, theconcentrtion of the soluble vanadium compound present in thepolymerization system. The organoaluminum compound (d-1) may be suppliedthereto at a mole ratio of the aluminum atom versus the vanadium atom(Al/V) in the polymerization system of at least 2, preferably in therange from 2 to 50, more preferably from 3 to 20.

The soluble vanadium compound (c-1) and the organoaluminum compound(d-1) are supplied usually under dilution with the above-mentionedhydrocarbon in solvent and/or by the liquid comonomer(s). Here, it ispreferable that the soluble vanadium compound (c-1) is diluted therebyto the above-mentioned concentration, while the organoaluminum compound(d-1) may preferably be supplied to the polymerization system underadjustment of its concentration at, for example, a value not exceeding50 times the concentration thereof in the polymerization system.

In case a catalyst based on metallocene composed of the metallocene(c-2) and the organoaluminum-oxy compound (d-2) or the ionizing ioniccompound (e-1) is used, the concentration of the metallocene (c-2) inthe polymerization system may usually be in the range from 0.00005 to0.1 mmol/liter (polymerization volume), preferably from 0.0001 to 0.05mmol/liter. The organoaluminum-oxy compound (d-2) is supplied thereto ata mole ratio of aluminum to the transition metal of the metallocene(Al/transition metal) in the polymerization system in the range from 1to 10,000, preferably from 10 to 5,000.

The ionizing ionic compound (e-1) may be supplied to the polymerizationsystem at a mole ratio of the ionizing ionic compound (e-1) to themetallocene (c-2), namely, (ionizing ionic compound (e-1))/(metallocene(c-2)), in the polymerization system in the range from 0.5 to 20,preferably from 1 to 10.

In case the organoaluminum compound (d-1) is used, it is used usually inan approximate amont of 0-5 mmol/liter (polymerization volume),preferably 0-2 mmol/liter.

When the copolymerization is carried out in the presence of the catalystbased on vanadium, the copolymerization is carried out usually under thecondition of a temperature in the range from −50° C. to +100° C.,preferably from −30° C. to +80° C., more preferably from −20° C. to +60°C., under a pressure exceeding above 0 up to 4.9 MPa (50 kgf/cm²,gauge), preferably exceeding above 0 up to 2.0 MPa (20 kgf/cm², gauge).

When the copolymerization is carried out in the presence of the catalystbased on metallocene, the copolymerization is carried out usually underthe condition of a temperature in the range from −20° C. to +150° C.,preferably from 0° C. to +120° C., more preferably from 0° C. to +100°C., under a pressure exceeding above 0 up to 7.8 MPa (80 kgf/cm²,gauge), preferably exceeding above 0 up to 4.9 MPa (50 kgf/cm², gauge).

On the copolymerization, the α-olefin (A1) and the non-conjugated cyclicpolyene (A2) or, on the other hand, the α-olefin (A1), thenon-conjugated cyclic polyene (A2) and the non-conjugated linear polyene(A3) are supplied to the polymerization system in such a rate that thesaid copolymer based on non-conjugated cyclic polyene is obtained in thecomposition specified above. It is permissible on the copolymerizationto use a molecular weight regulator, such as hydrogen.

By performing the copolymerization as described above, the copolymerbased on non-conjugated cyclic polyene according to the presentinvention is obtained usually in a form of polymerization liquorcontaining it. This polymerization liquor is treated in a usual way toobtain the copolymer based on non-conjugated cyclic polyene.

The rubber composition according to the present invention is a rubbercomposition comprising the copolymer based on non-conjugated cyclicpolyene {in the following, denoted as the non-conjugated cyclic polyene(A)} and a rubber based on diene (B), wherein the proportion of thesecomponents in weight ratio, i.e. the non-conjugated cyclic polyene(A)/rubber based on diene (B), may favorably be in the range from 60/40to 0.1/99.9, preferably from 50/50 to 1/99, more preferably from 40/60to 5/95. When the proportion of the contents of these components is inthe range given above, tires produced therewith exhibit superior brakingperformance and excellent driving fuel cost aspect in a compatiblemanner and the rubber composition using it can reveal superior featuresin the improved weatherability, in the controlled damping rate and soon, wherein the closer the weight ratio to the above-mentionedpreferable range is, the more superior the rubber composition in thebalance between the braking performance and the driving fuel cost aspectand in the improvement of the weatherability and controlled damping ratewill be.

As the diene-based rubber (B) to be incorporated according to thepresent invention, every known rubber based on diene having doublebond(s) in the main chain can be used without restriction, whereinpreference is given to a polymer product or a copolymer rubber made froma conjugated diene compound as the main comonomer. The diene-basedrubber (B) encompasses natural rubber (NR) and hydrogenated rubber. Forthe diene-based rubber (B), those which have iodine values not lowerthan 100, preferably not lower than 200, more preferably not lower than250 are preferred.

Concrete examples of the diene-based rubber (B) include natural rubber(NR), isoprene rubber (IR), styrene/butadiene rubber (SBR), butadienerubber (BR), chloroprene rubber (CR), acrylonitrile/butadiene rubber(NBR), nitrile rubber and hydrogenated nitrile rubber. Among them,natural rubber (NR), isoprene rubber (IR), styrene/butadiene rubber(SBR) and butadiene rubber (BR) are preferred, wherein specialpreference is given to styrene/butadiene rubber (SBR). As thediene-based rubber (B), one single kind of rubber or a blend of two ormore kinds of rubbers may be employed.

As the natural rubber (NB), those standardized by Green Book(international package standards for qualities of commercial grades ofnatural rubber) may be used.

As the isoprene rubber (IR), those having specific gravities in therange from 0.91 to 0.94 and Mooney viscosities (ML₁₊₄, 100° C.) in therange from 30 to 120 may favorably be employed.

As the styrene/butadiene rubber (SBR), those having specific gravitiesin the range from 0.91 to 0.98 and Mooney viscosities (ML₁₊₄, 100° C.)in the range from 20 to 120 may favorably be employed.

As the butadiene rubber (BR), those having specific gravities in therange from 0.90 to 0.95 and Mooney viscosities (ML₁₊₄, 100° C.) in therange from 20 to 120 may favorably be employed.

The rubber composition according to the present invention is a rubbercomposition capable of being vulcanized. While it may be used as anon-vulcanized product, more excellent characteristic features may berevealed by using it as a vulcanized product. The vulcanization may becarried out, for example, by a method of heating with employment of avulcanizing agent (F) or by a method of irradiation of electron beamwithout using vulcanizing agent (F).

When the rubber composition according to the present invention isvulcanized by heating it, compounds constituting a vulcanizer system,including a vulcanizing agent (F), a vulcanization accelerator and avulcanization assistant, may be admixed to the rubber composition.

As the vulcanizing agent (F), for example, sulfur, compounds based onsulfur and organic peroxides may be employed.

The morphological state of sulfur is not specifically restricted and,for example, powdery sulfur, precipitated sulfur, colloidal sulfur,surface-treated sulfur and insoluble sulfur may be employed.

As the compound based on sulfur mentioned above, there may be enumeratedconcretely, for example, sulfur chloride, sulfur dichloride, polymericpolysulfide, morpholine disulfide, alkylphenol disulfide,tetramethylthiuram disulfide and selenium dimethyldithiocarbamate.

As the organic peroxide mentioned above, there may be enumeratedconcretely, for example, alkyl peroxides, such as dicumyl peroxide,di-tert-butyl peroxide, di-tert-butylperoxy-3,3,5-trimethylcyclohexane,tert-butylcumyl peroxide, di-tert-amyl peroxide,2,5-dimethyl-2,5-di(tert-butylperoxy)hexine-3,2,5-dimethyl-2,5-di(benzoylperoxy)hexane,2,5-dimethyl-2,5-di(tert-butylperoxy)hexane,α,α′-bis(tert-butylperoxy-m-isoprpyl)benzene and tert-butylhydroperoxide; peroxyesters, such as tert-butyl peroxyacetate,tert-butyl peroxyisobutyrate, tert-butyl peroxypivalate, tert-butylperoxymaleate, tert-butyl peroxyneodecanoate, tert-butyl peroxybenzoateand di-tert-butyl peroxyphthalate; and ketone peroxides, such asdicyclohexanone peroxide. They may be employed in a combination of twoor more.

Among them, organic peroxides having one minute half-value periodtemperatures in the range from 130 to 200° C. are preferred, in whichconcretely dicumyl peroxide, di-tert-butyl peroxide,di-tert-butylperoxy-3,3,5-trimethylcyclohexane, tert-butylcumylperoxide, di-tert-amyl peroxide and tert-butyl hydroperoxide arepreferable.

Among the above-recited vulcanizing agents (F), in particular, sulfurand compounds based on sulfur, especially sulfur is favorable, since arubber composition exhibiting superior characteristic properties can beobtained by the use thereof.

In case the vulcanizing agent (F) is sulfur or a compound based onsulfur, it may be incorporated in an amount of 0.1-10 parts by weight,preferably 0.5-5 parts by weight, per 100 parts by weight of the totalsum of the copolymer based on non-conjugated cyclic polyene (A) plus thediene-based rubber (B).

In case the vulcanizing agent (F) is an organic peroxide, it may beincorporated in an amount of 0.05-15 parts by weight, preferably 0.15-5parts by weight, per 100 parts by weight of the total sum of thecopolymer based on non-conjugated cyclic polyene (A) plus thediene-based rubber (B).

When sulfur or a compound based on sulfur is used as the vulcanizingagent (F), it is preferable to use concurrently a vulcanizingaccelerator.

As the vulcanizing accelerator, there may be exemplified concretely,sulfenamides, such as N-cyclohexyl-2-benzothiazole sulfenamide (CBS),N-oxydiethylene-2-benzothiazole sulfenamide andN,N-diisopropyl-2-benzothiazole sulfenamide; thiazole compounds, such as2-mercaptobenzothiazole (MBT),2-(2,4-dinitrophenyl)mercaptobenzothiazole,2-(2,6-diethyl-4-morpholinothio)benzothiazole,2-(4′-morpholinodithio)benzothiazole and dibenzothiazyl disulfide;guanizine compounds, such as diphenylguanizine, triphenylguanizine,diorthonitrile guanidine, orthonitrile biguanide and diphenylguanizinephthalate; aldehydoamino and aldehydoammonium compounds, such asacetaldehyde-aniline reaction products, butylaldehydeaniline condensedproducts, hexamethylenetetramine and acetaldehyde ammonia; imidazolinecompounds, such as 2-mercaptoimidazoline; compounds based on thiourea,such as thiocarbanilide, diethylthiourea, dibutylthiourea,trimethylthiourea and di-o-tolylthiourea; thiuram compounds, such astetramethylthiuram monosulfide, tetramethylthiuram disulfide (TMTD),tetraethylthiuram disulfide, tetrabutylthiuram disulfide,pentamethylenethiuram tetrasulfide and dipentamethylenethiuramtetrasulfide (DPTT); compounds based on dithioacid salt, such as zincdimethyldithiocarbamate, zinc diethyldithiocarbamate, zincdi-n-butyldithiocarbamate, zinc ethylphenyldithiocarbamate, zincbutylphenyldithiocarbamate, sodium dimethyldithiocarbamate, seleniumdimethyldithiocarbamate and t llurium dimethyldithiocarbamate;xanthates, such as zinc dibutyl xanthogenate; and zinc white.

The vulcanizing accelerator mentioned above may favorably beincorporated in an amount in the range from 0.1 to 20 parts by weight,preferably from 0.2 to 10 parts by weight, per 100 parts by weight ofthe total sum of the copolymer based on non-conjugated cyclic polyene(A) plus the diene-based rubber (B).

In the case of using an organic peroxide as the vulcanizing agent (F),it is favorable to use concurrently a vulcanization assistant in anamount of 0.5-2 moles per one mole of the organic peroxide, preferablyin an amount nearly equivalent thereto.

As the vulcanization assistant, there may be exemplified concretely, inaddition to sulfur and a compound based on quinone dioxime, such asp-quinone dioxime, a polyfunctional monomer, for example, a compoundbased on (meth)acrylate, such as trimethylol-propane triacrylate orpolyethylene glycol dimethacrylate; an allyl compound, such as diallylphthalate or triallyl cyanurate; a compound based on maleimide, such asm-phenylene-bis-maleimide; and divinylbenzene.

The rubber composition according to the present invention may contain afiller (G) comprising, for example, a reinforcing agent and softener.

As the reinforcing agent, there may be enumerated, for example, carbonblack, such as SRF, GPF, FEF, MAF, HAF, ISAF, SAF, FT and MT;surface-treated carbon black, prepared by subjecting the above carbonblack product to surface treatment using, for example, a silane couplingagent; and other inorganic fillers, sich as silica, activated calciumcarbonate, light calcium carbonate, heavy calcium carbonate,micropulverous talc, talc, micropulverous silica and clay.

The amount of the reinforcing agent to be compounded may favorably be atmost 300 parts by weight, preferably in the rage from 10 to 300 parts byweight, more preferably from 10 to 200 parts by weight, per 100 parts byweight of the total sum of the copolymer based on non-conjugated cyclicpolyene (A) and the diene-based rubber (B).

Using rubber composition containing such an amount of reinforcing agent,a vulcanized rubber exhibiting improved mechanical properties, such astensile strength, tear strength and abrasion resistance, can beobtained. It is possible to increase the hardness without deterioratingother material properties of the vulcanized rubber and to attainreduction of costs.

As the softener mentioned above, those which have conventionally beenincorporated in rubbers may widely be used. Concrete examples includesofteners based on petroleum, such as process oils, lubricating oils,paraffines, liquid paraffine, petroleum asphalt and vaseline; softenersbased on coal tar, such as coal tar and coal tar pitch; softeners basedon fatty oil, such as castor oil, linseed oil, rapeseed oil and palmoil; waxes, such as tall oil, faktis, beeswax, carnauba wax and lanolin;fatty acids and fatty acid salts, such as ricinolic acid, palmitic acid,barium stearate, calcium stearate and zinc laurate; plasticizers basedon esters, such as dioctyl phthalate, dioctyl adipate and dioctylsebacate; and synthetic polymeric substances, such as petroleum resin,atactic polypropylene and cumarone-indene resin. Among them, those basedon petroleum are preferred, with particular preference to process oils.

The amount of the softener to be compounded may favorably be at most 200parts by weight, preferably in the range from 10 to 200 parts by weight,more preferably from 10 to 150 parts by weight, per 100 parts by weightof the total sum of the copolymer based on non-conjugated cyclic polyene(A) plus the diene-based rubber (B).

The rubber composition according to the present invention may contain,in addition to the components mentioned above, as other constituents,for example, compounds constituting foaming agent systems, such asfoaming agent and forming assistant, antioxidant (stabilizer),processing assistant, plasticizer, colorant and other rubber additivesand reagents. The amount of these other constituents may adequately bechosen for their sorts and amounts to be compounded.

The rubber composition according to the present invention, whencontaining compounds constituting a foaming agent system, such asfoaming agent and foaming assistant, may be processed by foamingmolding.

As the foaming agent, those which are used in general for foamingmolding of rubber may widely be employed. Concrete examples thereofinclude inorganic foaming agent, such as sodium bicarbonate, sodiumcarbonate, ammonium bicarbonate, ammonium carbonate and ammoniumnitrite; nitroso-compounds, such asN,N′-dimethyl-N,N′-dinitrosterephthalamide andN,N′-dinitrosopentamethylenetetramine; azo compounds, such asazodicarbonamide, azobisisobutyronitrile, azocyclohexylnitrile,azodiaminobenzene and barium azodicaboxylate; sulfonylhydrazides, suchas benzenesulfonylhydrazide, toluenesulfonylhydrazide,p,p′-oxybis(benzenesulfonylhydrazide) anddiphenylsulfon-3,3′-disulfonylhydrazide; and azides, such as calciumazide, 4,4-diphenyldisulfonyl azide and p-toluenesulfonyl azide. Amongthem, preference is given to nitroso-compounds, azo compounds andazides.

The foaming agent may be used in an amount in the range from 0.5 to 30parts by weight, preferably from 1 to 20 parts by weight, per 100 partsby weight of the total sum of the copolymer based on non-conjugatedcyclic polyene (A) plus the diene-based rubber (B). Using a rubbercomposition containing such an amount of the foaming agent, a foamedmolding having an apparent density of 0.03-0.8 g/cm² can be obtained.

Together with the foaming agent, a foaming assistant may be employed. Byusing concurrently a foaming assistant, such effects as lowering of thedecomposition temperature of the foaming agent, facilitation of thedecomposition and homogenization of the foam cells may be attained. Forsuch foaming assistant, there may be exemplified organic acids, such assalicylic acid, phthalic acid, stearic acid and oxalic acid, and ureaand its derivatives.

The foaming assistant may be used in an amount of 0.01-10 parts byweight, preferably 0.1-5 parts by weight, per 100 parts by weight of thetotal sum of the copolymer based on non-conjugated cyclic polyene (A)plus the diene-based rubber (B).

It is preferable that the rubber composition according to the presentinvention contains an antioxidant, since the service life of thematerial can be extended thereby. As the antioxidant, there may beexemplified concretely stabilizers based on aromatic secondary amine,such as phenylnaphthylamine, 4,4′-(α,α′-dimethylbenzyl)diphenylamine andN,N′-di-2-naphthyl-p-phenylenediamine; stabilizers based on phenol, suchas 2,6-di-tert-butyl-4-methylphenol andtetrakis-{methylene-3-(3′,5′-di-tert-butyl-4′-hydroxyphenyl)propionate}methane;stabilizers based on thioether, such asbis{2-methyl-4-(3-n-alkylthiopropionyloxy)-5-tert-butylphenyl}sulfideand so on; stabilizers based on benzimidazole, such as2-mercaptobenzimidazole and so on; stabilizers based on dithiocarbamate,such as nickel dibutyldithiocarbamate and so on; and stabilizers basedon quinoline, such as polymerized products of2,2,4-trimethyl-1,2-dihydroquinoline. These antioxidants may be usedalone or in a combination of two or more.

The antioxidant may be used in an amount of at most 5 parts by weight,preferably at most 3 parts by weight, per 100 parts by weight of thetotal sum of the copolymer based on non-conjugated cyclic polyene (A)plus the diene-based rubber (B).

As the processing assistant, those employed in general for rubbers maybe used widely. Concrete examples include acids, such as ricinoleicacid, stearic acid, palmitic acid and lauric acid and salts and estersof these acids, such as barium stearate, zinc stearate and calciumstearate.

The processing assistant may be used in an amount of at most 10 parts byweight, preferably at most 5 parts by weight, per 100 parts by weight ofthe total sum of the copolymer based on non-conjugated cyclic polyene(A) plus the diene-based rubber (B).

The rubber composition according to the present invention may beprepared from the copolymer based on non-conjugated cyclic polyene (A)and the diene-based rubber (B) together with the optionally incorporatedother constituents given above by a preparation technique used ingeneral for preparing rubber blends. It may be prepared by, for example,kneading the copolymer based on non-conjugated cyclic polyene (A), thediene-based rubber (B) and the optionally incorporated otherconstituents on an internal mixer, such as Bumbury's mixer, a kneader orIntermix, at a temperature of 80-170° C. for 3-10 minutes, and then,admixing thereto a vulcanizing agent (F) and, if necessary, avualcanizing accelerator, vulcanization assistant, foaming agent and soon, whereupon the resulting mixture is kneaded on a roll, such as openroll, or on a kneader at a roll temperature of 40-80° C. for a period of5-30 minutes, wherefrom the kneaded mass is taken out in portions. Inthis manner, the rubber composition (rubber blend) is prepared usuallyin a form of ribbon or sheet. In case where a low kneading temperatureis permitted in the internal mixer, the vulcanizing agent (F),vulcanizing accelerator, foaming agent and so on may concurrently beadmixed thereto.

The vulcanized product (vulcanized rubber) of the rubber compositionaccording to the present invention may be obtained usually by subjectingthe unvulcanized green rubber blend obtained as above to a preliminaryforming by various forming techniques using forming apparatuses, such asextrusion molding machine, calender, press machine, injection moldingmachine and transfer molding machine, into a contemplated form andeffecting the vulcanization of the resulting formed product,simultaneously with this forming or after the formed product has beentransferred to a vulcanization vessel, by heating it or irradiating itby an electron beam. In the case of foamed product, the unvulacanizedgreen rubber blend containing a foaming agent is subjected tovulcanization, as described above, wherein foaming of the formed productis attained simultaneously with the vulcanization so as to result in afoamed vulcanization product.

In the case of vulcanizing the rubber composition by heating, it isfavorable to heat the formed product in a heating vessel, in a heatingmode by hot air, glass beads fluidized bed, ultrahigh frequencyelectromagnetic wave (UHF), steam or hot molten-salt bath (LCM), at atemperature of 150-270° C. for 1-30 minutes.

In the case where the vulcanization is effected by irradiation withelectron beam without incorporating the vulcanizing agent (F), thepreliminarily formed rubber composition is irradiated with an electronbeam of an energy of 0.1-10 MeV, preferably 0.3-2 MeV so as to reach anabsorbed dose of 0.5-35 Mrad, preferably 0.5-10 Mrad.

For effecting the molding vulcanization, a mold may or may not be used.In the case wherein no mold is used, the rubber composition is moldedand vulcanized usually in a continuous manner.

The rubber composition according to the present invention renders theimprovement in the braking performance due to improvement of thegripping ability on the road face compatible with the improvement of thedriving fuel cost aspect due to reduction of rolling resistance duringsteady maneuvering, so that tires in which the superior brakingperformance is made compatible with the superior fuel cost aspect can beobtained by using the rubber composition according to the presentinvention as the raw material. The rubber composition according to thepresent invention is also excellent in the weatherability, resistance toozone, rubbery elasticity, mechanical strength, hardness and so on.

While the rubber composition according to the present invention may beused widely as starting material of various rubber articles, it can beused favorably as the rubber material for tires. Concrete examples ofrubber material for tires include materials for tire tread and for tireside wall. Above all, the rubber composition according to the presentinvention can most preferably be used for the material (raw material)for tire tread, whereby tires in which the superior braking performanceis made compatible with the superior driving fuel cost aspect withsuperior weatherability and anti-ozone performance can be obtained,wherein the characteristic properties of the rubber compositionaccording to the present invention are revealed most effectivelytherefor.

The rubber material for tires according to the present inventioncomprises the copolymer based on non-conjugated cyclic polyene (A),wherein it may be constituted of only the copolymer based onnon-conjugated cyclic polyene (A) or may comprise further constituents,such as other rubber(s) and additive(s). The content of the copolymerbased on non-conjugated polyene (A) in the rubber material for tiresaccording to the present invention may favorably be at least 3% byweight, preferably in the range from 5 to 90% by weight. The rubbermaterial for tires according to the present invention has superiorbraking performance which is made compatible with the superior drivingfuel cost aspect and the material is superior also in the rubberyelasticity, mechanical strength, weatherability, resistance to ozone,hardness and so on. As concrete examples of the rubber material fortires, those mentioned above may be recited.

The rubber material for tires according to the present inventioncomprises the rubber composition according to the present inventiongiven above, wherein it may be composed of only the rubber compositionaccording to the present invention or may comprise further constituents,such as other rubber(s) and additive(s). The content of the rubbercomposition according to the present invention in the rubber materialfor tires according to the present invention may favorably be at least3% by weight, preferably in the range from 5 to 90% by weight. Therubber material for tires according to the present invention hassuperior braking performance which is made compatible with the superiordriving fuel cost aspect and the material is superior also in therubbery elasticity, mechanical strength, weatherability, resistance toozone, hardness and so on. As concrete examples of the rubber materialfor tires, those mentioned above may be recited.

The tire tread according to the present invention is produced from theabove rubber material for tires according to the present invention,wherein it may be produced from only the rubber material according tothe present invention or may be produced under addition of furtherconstituents, such as other rubber(s) and additive(s). The content ofthe rubber material according to the present invention in the tire treadaccording to the present invention may favorably be at least 3% byweight, preferably in the range from 5 to 90% by weight. The tire treadproduced from the rubber composition or the rubber material for tiresaccording to the present invention under vulcanization has superiorbraking performance which is made compatible with the superior drivingfuel cost aspect and the tire tread is superior also in theweatherability, resistance to ozone and so on.

The tires according to the present invention is provided with the tiretread according to the present invention described above. The tiresaccording to the present invention exhibit superior braking performancewhich is made compatible with the superior driving fuel cost aspect andthe tires are superior also in the weatherability, resistance to ozoneand so on.

As described above, the copolymer based on non-conjugated cyclic polyeneaccording to the present invention is a novel materal and is useful, forexample, for the constituent of rubber material for tires.

The rubber composition according to the present invention contains acopolymer based on non-conjugated cyclic polyene having specificmaterial properties, on the one hand, and a rubber based on diene, onthe other hand, in a specific proportion, from which tires exhibiting asuperior braking performance and, in a compatible manner therewith, asuperior driving fuel cost aspect can be produced.

The rubber material for tires according to the present inventioncomprises the above-mentioned copolymer based on non-conjugated cyclicpolyene or the rubber composition, in which the superior brakingperformance is made compatible with the superior driving fuel costaspect, and the material is superior also in the rubbery elasticity,mechanical strength, weatherability,resistance to ozone, hardness and soon.

The tire tread according to the present invention is produced from theabove-mentioned rubber material for tires and has superior brakingperformance which is made compatible with the superior driving fuel costfeature and the tire tread is superior also in the weatherability,resistance to ozone and so on.

The tires according to the present invention are provided with theabove-mentioned tire tread and have superior braking performance and,compatible therewith, superior driving fuel cost aspect and the tiresare superior also in the weatherability, resistance to ozone and so on.

THE BEST MODE FOR EMBODYING THE INVENTION

Below, the present invention will be described by way of Examples.

EXAMPLES Example 1

(Synthesis of a Copolymer based on Non-conjugated Cyclic Polyene)

An autoclave made of a stainless steel (SUS) of a capacity of 2 litersof which internal atmosphere had sufficiently been replaced withnitrogen was charged with 970 ml of heptane deprived of impurities and30 ml of ENB at 23° C. and the autoclave made of SUS was heated up to50° C. On reaching 50° C., ethylene was pressed into the autoclave untilthe total pressure of 0.78 MPa (8 kgf/cm², gauge) was reached. Thereintowas then pressed 1.0 mmol of triisobutylaluminum, whereupon 5 ml of atoluene solution of racemi-isopropylidenebis-(1-indenyl)zirconiumdichloride/methylaluminoxane (with Zr concentration of 0.001 mmol/ml andAl concentration of 0.5 mmol/ml) were pressed thereinto. A commercialproduct of methylaluminoxane (of TOSOH AKZO K.K.) was used.

The polymerization was effected for 10 minutes after the introduction ofthe toluene solution of racemi-isopropylidenebis(1-indenyl)zirconiumdichloride/methylaluminoxane. The original internal pressure of theautoclave directly after the introduction of the solution was maintainedby pressing ethylene thereinto. After a prescribed reaction duration hadbeen elapsed, the polymerization was terminated by introducing 3 ml ofmethanol to the autoclave by boosting with nitrogen.

As a result, 28 grams of an ethylene/ENB copolymer having an ethylenecontent of 87.6 mole %, an ENB content of 12.4 mole %, an intrinsicviscosity [η] of 1.1 dl/g and an iodine value of 80 were obtained. TheTg of this copolymer determined by a dynamic rheological observation was13° C. The results are recited in Table 1.

Example 2

Polymerization was carried out in the same manner as in Example 1 execptthat the charged amount of ENB was changed. The r sults are recited inTable 1.

Example 3

(Synthesis of a Copolymer based on Non-conjugated Cyclic Polyene)

An autoclave made of a stainless steel (SUS) of a capacity of 2 litersof which internal atmosphere had sufficiently been replaced withnitrogen was charged with 950 ml of heptane deprived of impurities and50 ml of ENB at 23° C. and the autoclave made of SUS was heated up to80° C. On reaching 80° C., 70 N ml of hydrogen were added thereto,whereupon ethylene was pressed into the autoclave until the totalpressure of 0.78 MPa (8 kgf/cm², gauge) was reached. Then, 0.35 mmol oftriisobutylaluminum was first pressed thereinto, whereupon 1.5 ml (0.003mmol) of a hexane solution of(tert-butylamido)dimethyl(tetramethyl-η⁵-cyclopentadienyl)silanetitaniumdichloride of a concentration of 0.002 mmol/ml and 5 ml (0.02 mmol) of ahexane slurry of (C₆H₅)₃CB(C₆F₅)₄ of a concentration of 0.004 mmol/mlwere pressed thereinto individually of each other.

The polymerization was performed for three minutes after theintroduction of (C₆H₅)₃CB(C₆F₅)₄. The original internal pressure of theautoclave directly after the introduction of the solution was maintainedby pressing ethylene thereinto. After a prescribed reaction duration hadbeen elapsed, the polymerization was terminated by introducing 3 ml ofmethanol to the autoclave by boosting with nitrogen.

As a result, 15 grams of an ethylene/ENB copolymer having an ethylenecont nt of 88.2 mole %, an ENB content of 11.8 mole %, an intrinsicviscosity [η] of 1.2 dl/g and an iodine value of 76 were obtained. TheTg of this copolymer determined by a dynamic Theological observation was12° C. The results are recited in Table 1.

Example 4

(Synthesis of a Copolymer based on Non-conjugated Cyclic Polyene)

An autoclave made of a stainless steel (SUS) of a capacity of 2 litersof which internal atmosphere had sufficiently been replaced withnitrogen was charged with 990 ml of heptane deprived of impurities and10 ml of ENB at 23° C. and the autoclave made of SUS was heated up to30° C. On reaching 30° C., 100 N ml of hydrogen were added thereto,whereupon ethylene was pressed into the autoclave until the totalpressure of 0.59 MPa (6 kgf/cm², gauge) was reached. Then, 1.0 mmol ofethylaluminum sesquichloride was first pressed thereinto, whereupon 10ml (0.1 mmol) of a hexane solution of dichloroethoxyvanadium oxide of aconcentration of 0.01 mmol/ml were pressed thereinto.

The polymerization was performed for two minutes after the introductionof the hexane solution of dichloroethoxyvanadium oxide. The originalinternal pressure of the autoclave directly after the introduction ofthe solution was maintained by pressing ethylene thereinto. After aprescribed reaction duration had been elapsed, the polymerization wasterminated by introducing 10 ml of methanol to the autoclave by boostingwith nitrogen.

As a result, 7 grams of an thylene/ENB copolymer having an ethylenecontent of 87.1 mole %, an ENB content of 12.9 mole %, an intrinsicviscosity [η] of 1.3 dl/g and an iodine value of 82 were obtained. TheTg of this copolymer determined by a dynamic rheological observation was14° C. The results are recited in Table 1.

Example 5

(Synthesis of a Copolymer based on Non-conjugated Cyclic Polyene)

An autoclave made of a stainless steel (SUS) of a capacity of 2 litersof which internal atmosphere had sufficiently been replaced withnitrogen was charged with 860 ml of heptane deprived of impurities and40 ml of ENB at 23° C. and the autoclave made of SUS was heated up to80° C. On reaching 80° C., 20 N ml of hydrogen were added thereto,whereupon propylene was pressed into the autoclave up to a pressure of0.25 MPa (2.5 kgf/cm², gauge) and finally, ethylene was pressedthereinto until a total pressure of 0.59 MPa (6 kgf/cm², gauge) wasreached. Then, 0.35 mmol of triisobutylaluminum was first pressedthereinto, whereupon 1.5 ml (0.003 mmol) of a hexane solution of(tert-butylamido)dimethyl(tetramethyl-η⁵-cyclopentadienyl)silanetitaniumdichloride of a concentration of 0.002 mmol/ml and 2.5 ml (0.01 mmol) ofa toluene solution of (C₆H₅)₃CB(C₆F₅)₄ of a concentration of 0.004mmol/ml were pressed thereinto individually of each other.

The polymerization was performed for ten minutes after the introductionof (C₆H₅)₃CB(C₆F₅)₄. The original internal pressure of the autoclavedirectly after the introduction of the solution was maintained bypressing ethylene thereinto. After a prescribed reaction duration hadbeen elapsed, the polymerization was terminated by introducing 3 ml ofmethanol to the autoclave by boosting with nitrogen.

As a result, 39.7 grams of an ethylene/propylene/ENB copolymer having anethylene content of 49.6 mole %, a propylene content of 43.4 mole % andan ENB content of 7.0 mole %, an intrinsic viscosity [η] of 1.1 dl/g andan iodine value of 64 were obtained. The Tg of this copolymer determinedby a dynamic rheological observation was −18° C. The results are recitedin Table 2.

Example 6

(Synthesis of a Copolymer based on Non-conjugated Cyclic Polyene)

An autoclave made of a stainless steel (SUS) of a capacity of 2 litersof which internal atmosphere had sufficiently been replaced withnitrogen was charged with 836.7 ml of heptane deprived of impurities, 50ml of ENB and 13.3 ml of dimethyldecatriene (DMDT) at 23° C. and theautoclave made of SUS was heated up to 80° C. On reaching 80° C.,propylene was pressed into the autoclave up to a pressure of 0.25 MPa(2.5 kgf/cm², gauge) and then, ethylene was pressed thereinto until atotal pressure of 0.59 MPa (6 kgf/cm², gauge) was reached. Then, 0.7mmol of triisobutylaluminum was first pressed thereinto, whereupon 2.0ml (0.004 mmol) of a hexane solution of(tert-butylamido)dimethyl(tetramethyl-η⁵-cyclopentadienyl)silanetitaniumdichloride of a concentration of 0.002 mmol/ml and 2.5 ml (0.01 mmol) ofa toluene solution of (C₆H₅)₃CB(C₆F₅)₄ of a concentration of 0.004mmol/ml were pressed thereinto individually of each other.

The polymerization was performed for 30 minutes after the introductionof (C₆H₅)₃CB(C₆F₅)₄. The original internal pressure of the autoclavedirectly after the introduction of the solution was maintained bypressing ethylene thereinto. After a prescribed reaction duration hadbeen elapsed, the polymerization was terminated by introducing 3 ml ofmethanol to the autoclave by boosting with nitrogen.

As a result, 17.0 grams of an ethylene/propylene/ENB/DMDT copolymerhaving an ethylene content of 57.8 mole %, a propylene content of 34.1mole %, an ENB content of 6.8 mole %, a DMDT content of 1.3 mole %, anintrinsic viscosity [η] of 1.1 dl/g and an iodine value of 73 wereobtained. The results are recited in Table 2.

TABLE 1 Example 1 2 3 4 ENB charged (ml) 30 60 50 10 Copolymercomposition Ethylene (mole %) 87.6 81.5 88.2 87.1 ENB (mole %) 12.4 18.511.8 12.9 Material properties [η]^(*1) (dl/g) 1.1 1.1 1.2 1.3 Tg^(*2) (°C.) 13 26 12 14 Iodine value 80 104 76 82 Notes in Tables 1 and 2:^(*1)[η]: intrinsic viscosity [η], determined in decalin at 135° C.^(*2)Tg: determined by preparing a test specimen of a ribbon of 10 mmwidth, 2 mm thickness and 30 mm length and subjecting this specimen to adynamic viscoelasticity test using a tester of Model RDS II of the firmRheometric at a vibration frequency of 10 Hz, a strain of 0.1%, and atemperature elevation rate of 2° C./min., wherein the peak temperatureon damping factor (tan δ) is assumed as Tg.

TABLE 2 Example 5 6 Copolymer composition Ethylene (mole %) 49.6 57.8Propylene (mole %) 43.4 34.1 ENB (mole %) 7.0 6.8 DMDT (mole %) — 1.3Material properties [η]^(*1) (dl/g) 1.1 1.1 Tg^(*2) (° C.) −18 −19Iodine value (g/100 g) 64 73 Notes in Tables 1 and 2: ^(*1)[η]:intrinsic viscosity [η], determined in decalin at 135° C. ^(*2)Tg:determined by preparing a test specimen of a ribbon of 10 mm width, 2 mmthickness and 30 mm length and subjecting this specimen to a dynamicviscoelasticity test using a tester of Model RDS II of the firmRheometric at a vibration frequency of 10 Hz, a strain of 0.1%, and atemperature elevation rate of 2° C./min., wherein the peak temperatureon damping factor (tan δ) is assumed as Tg.

Example 7

Using the components as given in Table 3 in a proportion given therein,a green unvulcanized rubber blend was prepared by kneading them on anopen roll (60° C. for the fore side roll/60° C. for the aft side roll;16 r.p.m. of fore side roll/18 r.p.m. of aft side roll). This greenrubber blend was processed on a press heated at 160° C. for 20 minutesinto a vulcanized sheet, with which the following tests were carriedout. The results are recited in Table 4.

TABLE 3 Composition (part by weight) Example 7 Copolymer of Example1^(*1) 10 SBR^(*2) 90 Zinc white 5 Stearic acid 1 Carbon black HAF^(*3)50 Naphthene base oil^(*4) 5 Vulcan. accelerator CBZ^(*5) 0.5 Vulcan.accelerator DPG^(*6) 1.0 Sulfur 2.0 ^(*1)Copolymer of Example 1: seeTable 1 ^(*2)SBR = a styrene/butadiene rubber NIPPOL 1502 (trademark) ofNippon Zeon Co., Ltd., with iodine value of 357 ^(*3)Carbon black HAF =HAF ASAHI #70 (trademark), a product of Asahi Carbon K. K.^(*4)Naphthene base oil: SUNSEN 4240 (trademark) of Nippon Sun Oil Co.,Ltd. ^(*5)Vulcan. accelerator CBZ: SANCELER CM (trademark) of SanshinChemical Industry Co., Ltd. ^(*6)Vulcan. accelerator DPG: SANCELER D(trademark) of Sanshin Chemical Industry Co., Ltd.

Comparative Example 1

The procedures of Example 7 wer followed except that the copolymer basedon non-conjugated cyclic polyene was not used and 100 parts by weight ofSBR were incorporated. The results are recited in Table 4.

TABLE 4 Example Comp. 7 Example 1 T_(B) ^(*1) (MPa) 21 25 E_(B) ^(*2)(%) 470 470 HS^(*3) (JIS A) 63 61 Resist. to ozone^(*4) unvaried C-4 tanδ^(*5)  (0° C.) 0.23 0.17 tan δ^(*5) (50° C.) 0.15 0.16 ^(*1)T_(B) =Tensile strength at break (JIS K 6301) ^(*2)E_(B) = Elongation at break(JIS K 6301) ^(*3)HS (JIS A) = Hardness ^(*4)Resist. to ozone:determined in accordance with the prescription of JIS K 6301 under thecondition of 40° C., an ozone concentration of 50 pphm and 24 hours. Thenumber (i) and size and depth (ii) of cracks occurred are observed andassessed by the following criterion and the state of deterioration isrecorded by combining (i) and (ii).  (i) Number of cracks:   A: scarcenumber of cracks are observed   B: a large number of cracks are observed  C: innumerable number of cracks are observed  (ii) Size and depth ofcracks:   1: not visible by naked eye but visible by a magnifying glassof magnification of 10 times   2: visible by naked eye   3: deep andrelatively large (less than 1 mm)   4: deep and large (more than 1 mm,less than 3 mm)   5: at least 3 mm or nearly going to break ^(*5)tan δ:The tan δ value (damping factor) of the rubber composition at 0° C. istaken as the parameter of braking performance of tire. The higher thetan δ value at 0° C., the better the braking performance will be. Thetan δ value (damping factor) at 50° C. of the rubber composition istaken as the parameter of driving fuel cost aspect of automobile. Thelower the tan δ value at 50° C., the higher the # fuel cost aspect willbe. Determination of tan δ (damping factor) is carried out, using a testspecimen of 10 mm width, 2 mm thickness and 30 mm length prepared fromthe rubber composition, on a testing apparatus RDS-II of the firmRheometric from the temperature dispersion of viscoelasticity observedat 1 Hz (6.28 rad/sec).

Example 8

Using the components as given in Table 5 in a proportion given therein,a green unvulcanized rubber blend was prepared by kneading them on anopen roll (60° C. for the fore side roll/60° C. for the aft side roll;16 r.p.m. of fore side roll/18 r.p.m. of aft side roll). This greenrubber blend was processed on a press heated at 160° C. for 20 minutesinto a vulcanized sheet, with which the following tests were carriedout. The results are recited in Table 6.

TABLE 5 Composition (part by weight) Example 8 Copolymer of Example5^(*1) 10 SBR^(*2) 90 Zinc white 3 Stearic acid 1 Carbon black HAF^(*3)50 Vulcan. accelerator CBZ^(*4) 0.5 Sulfur 1.75 ^(*1)Copolymer ofExample 5: see Table 1 ^(*2)SBR = a styrene/butadiene rubber NIPPOL 1502(trademark) of Nippon Zeon Co., Ltd., with iodine value of 357^(*3)Carbon black HAF = HAF ASAHI #70 (trademark), a product of AsahiCarbon K. K. ^(*4)Vulcan. accelerator CBZ: SANCELER CM (trademark) ofSanshin Chemical Industry Co., Ltd.

Comparative Example 2

The procedures of Example 8 were followed except that the copolymerbased on non-conjugated cyclic polyene was not used and 100 parts byweight of SBR were incorporated. The results are recited in Table 6.

TABLE 6 Example Comp. 8 Example 2 T_(B) ^(*1) (MPa) 26.7 28.1 E_(B)^(*2) (%) 390 360 HA^(*3) (Shore A) 70 70 tan δ^(*4)  (0° C.) 0.2110.162 tan δ^(*4) (60° C.) 0.141 0.134 ^(*1)T_(B) = Tensile strength atbreak (JIS K 6301) ^(*2)E_(B) = Elongation at break (JIS K 6301) ^(*3)HA(Shore A) = Hardness ^(*4)tan δ: The tan δ value (damping factor) of therubber composition at 0° C. is taken as the parameter of brakingperformance of tire. The higher the tan δ value at 0° C., the better thebraking performance will be. The tan δ value (damping factor) at 60° C.of the rubber composition is taken as the parameter of driving fuel costaspect of automobile. The lower the tan δ value at 60° C., the higherthe # fuel cost feature will be. The tan δ (damping factor) isdetermined, using a test specimen of 10 mm width, 2 mm thickness and 30mm length prepared from the rubber composition, on a testing apparatusRDS-II of the firm Rheometric from the temperature dispersion ofviscoelasticity observed under a condition of 0.05% strain and 10 Hz.

INDUSTRIAL APPLICABILITY

As described above, the copolymer based on non-conjugated cyclic polyeneand the rubber composition according to the present invention can beused as a constituent of, for example, rubber material for tires, tiretreads and tires.

What is claimed is:
 1. A random copolymer based on non-conjugated cyclicpolyene comprising structural units originated from one or moreα-olefins (A1) and originated from one or more non-conjugated cyclicpolyenes (A2), the said random copolymer having characteristic featurescomprising: a content of the structural unit(s) originated from the saidone or more α-olefins (A1) in the range of 93 to 70 mole %, a content ofthe structural units originated from the said one or more non-conjugatedcyclic polyenes (A2) in the range of 7 to 30 mole %, an intrinsicviscosity [η], determined in decahydronaphthalene at 135° C., in therange of 0.01 to 20 dl/g, a glass transition temperature (Tg) of −30° C.to +40° C., and an iodine value in the range of 35 to
 150. 2. A randomcopolymer based on non-conjugated cyclic polyene comprising structuralunits originated from one or more α-olefins (A1), originated from one ormore non-conjugated cyclic polyenes (A2) and originated from one or morenon-conjugated linear polyenes (A3), the said random copolymer havingcharacteristic features comprising: a content of the structural unit(s)originated from the said one or more α-olefins (A1) in the range of 97.9to 55 mole %, a content of the structural unit originated from the saidone or more non-conjugated cyclic polyenes (A2) in the range of 2 to 30mole %, a content of the structural unit originated from the said one ormore non-conjugated linear polyenes (A3) in the range from 0.1 to 15mole %, an intrinsic viscosity [η], determined in decahydronaphthaleneat 135° C., in the range of 0.01 to 20 dl/g, a glass transitiontemperature (Tg) −30° C. to +40° C., and an iodine value in the range of5 to
 150. 3. The random copolymer as claimed in claim 1 or 2, whereinthe structural unit(s) originated from one or more α-olefins (A1)comprise at least a structural unit originated from ethylene in whichthe mole ratio of (the structural unit originated from ethylene) versus(the structural unit(s) originated from other α-olefin(s) having 3 ormore carbon atoms) is in the range from 100/0 to 1/99.
 4. The randomcopolymer as claimed in claim 1 or 2, wherein the structural unit(s)originated from one or more α-olefins (A1) comprise at least astructural unit originated from ethylene in which the mole ratio of (thestructural unit originated from ethylene) versus (the structural unit(s)originated from other α-olefin(s) having 3 or more carbon atoms) is inthe range from 100/0 to 50/50.
 5. A rubber composition comprising (A) arandom copolymer based on non-conjugated cyclic polyene comprisingstructural units originated from one or more α-olefins (A1) andoriginated from one or more non-conjugated cyclic polyene (A2), the saidrandom copolymer having characteristic features comprising: a content ofthe structural unit(s) originated from the said one or more α-olefins(A1) in the range of 93 to 70 mole %; a content of the structural unitoriginated from the said one or more non-conjugated cyclic polyenes (A2)in the range of 7 to 30 mole %; an intrinsic viscosity [η], determinedin decahydronaphthalene at 135° C., in the range of 0.01 to 20 dl/g; aglass transition temperature (TG) of −30° C. to +40° C.; and an iodinevalue in the range of 35 to 150; and (B) a rubber based on diene,wherein the weight proportion of (the random copolymer based onnon-conjugated cyclic polyene) versus (the rubber based on diene),namely, (A/(B), is in the range of 60/40 to 0.1/99.9.
 6. A rubbercomposition comprising: (A) a random copolymer based on non-conjugatedcyclic polyene comprising structural units originated from one or moreα-olefins (A1) and originated from one or more non-conjugated cyclicpolyenes (A2) and originated from one or more non-conjugated linearpolyene (A3), the said random copolymer having characteristic featurescomprising: a content of the structural unit(s) originated from the saidone or more α-olefins (A1) in the range of 97.9 to 55 mole %; a contentof the structural unit originated from the said one or morenon-conjugated cyclic polyenes (A2) in the range of 2 to 30 mole %; acontent of the structural unit originated from the said one or morenon-conjugated linear polyene (A3) in the range of 0.1 to 15 mole %; anintrinsic viscosity [η], determined in decahydronaphthalene at 135° C.,in the range of 0.01 to 20 dl/g; a glass transition temperature (Tg) of−30° C. to +40° C.; and an iodine value in the range of 5 to 150, and(B) a rubber based on diene, wherein the weight proportion of (therandom copolymer based on non-conjugated cyclic polyene) versus (therubber based on diene), namely, (A)/(B), is in the range from 60/40 to0. 1/99.9.
 7. The rubber composition as claimed in claim 5 or 6, whereinthe structural unit(s) originated from one or more α-olefins (A1) in therandom copolymer based on non-conjugated cyclic polyene comprise atleast a structural unit originated from ethylene, wherein the mole ratioof (the structural unit originated from ethylene) versus (the structuralunit(s) originated from other α-olefin(s) having 3 or more carbon atoms)is in the range from 100/0 to 1/99.
 8. The rubber composition as claimedin claim 5 or 6, wherein the structural unit(s) originated from one ormore α-olefins (A1) in the random copolymer based on non-conjugatedcyclic polyene comprise at least a structural unit originated fromethylene, wherein the mole ratio of (the structural unit originated fromethylene) versus (the structural unit(s) originated from otherα-olefin(s) having 3 or more carbon atoms) is in the range from 100/0 to50/50.
 9. The random copolymer as claimed in claim 1, wherein thenon-conjugated cyclic polyene (A2) is that represented by the formula(1-1) given below:

in which m is an integer of 0 to 2, R¹ to R⁴ denote each, independentlyof each other, an atom or a residue selected from the group consistingof hydrogen atom, halogen atoms and hydrocarbon residues which may havedouble bond, wherein R¹ to R⁴ may be fused together to form a mono- orpolycyclic ring which may have double bond or wherein an alkylideneradical may be formed from the pair of R¹ and R² or R³ and R⁴ or,further R¹ and R³ or R² and R⁴ may be fused together so as to form adouble bond, with the proviso that at least one of R¹ to R⁴ stands foran unsaturated hydrocarbon residue having at least one double bond, incase the mono- or polycyclic ring formed from R¹ to R⁴ by being fusedtogether has no double bond, in case the pair of R¹ and R² or R³ and R⁴does not form an alkylidene radical and in case R¹ and R³ or R² and R⁴are not fused together to form an endocyclic bond.
 10. The randomcopolymer as claimed in claim 2, wherein the non-conjugated cyclicpolyene (A2) is that represented by the formula (1-1) given below:

in which m is an integer of 0 to 2, R¹ to R⁴ denote each, independentlyof each other, an atom or a residue selected from the group consistingof hydrogen atom, halogen atoms and hydrocarbon residues which may havedouble bond, wherein R¹ to R⁴ may be fused together to form a mono- orpolycyclic ring which may have double bond or wherein an alkylideneradical may be formed from the pair of R¹ and R² or R³ and R⁴ or,further, R¹ and R³ or R² and R⁴ may be fused together so as to form adouble bond, with the proviso that at least one of R¹ to R⁴ stands foran unsaturated hydrocarbon residue having at least one double bond, incase the mono- or polycyclic ring formed from R¹ to R⁴ by being fusedtogether has no double bond, in case the pair of R¹ and R² or R³ and R⁴does not form an alkylidene radical and in case R¹ and R³ or R² and R⁴are not fused together to form an endocyclic double bond.
 11. The randomcopolymer as claimed in claim 9, wherein the structural unit(s)originated from one or more α-olefins (A1) comprise at least astructural unit originated from ethylene in which the mole ratio of (thestructural unit originated from ethylene) versus (the structural unit(s)originated from other α-olefin(s) having 3 or more carbon atoms) is inthe range of from 100/0 to 1/99.
 12. The random copolymer as claimed inclaim 10, wherein the structural unit(s) originated from one or moreα-olefins (A1) comprise at least a structural unit originated fromethylene in which the mole ratio of (the structural unit originated fromethylene) versus (the structural unit(s) originated from otherα-olefin(s) having 3 or more carbon atoms) is in the range of from 100/0to 1/99.
 13. The random copolymer as claimed in claim 9, wherein thestructural unit(s) originated from one or more α-olefins (A1) compriseat least a structural unit originated from ethylene in which the moleratio of (the structural unit originated from ethylene) versus (thestructural unit(s) originated from other α-olefin(s) having 3 or morecarbon atoms) is in the range of from 100/0 to 50/50.
 14. The randomcopolymer as claimed in claim 10, wherein the structural unit(s)originated from one or more α-olefins (A1) comprise at least astructural unit originated from ethylene in which the mole ratio of (thestructural unit originated from ethylene) versus (the structural unit(s)originated from other α-olefin(s) having 3 or more carbon atoms) is inthe range of from 100/0 to 50/50.
 15. The random copolymer as claimed inclaim 2, wherein the non-conjugated linear polyene (A3) is representedby the formula (2-1) given below:

in which p and q is zero or 1 with the proviso that p and q are not zerosimultaneously, f is an integer of zero to 5 with the proviso that f isnot zero when both p and q are 1, g is an integer of 1 to 6, R¹, R², R³,R⁴, R⁵, R⁶ and R⁷ denote each, independently of each other, hydrogenatom or an alkyl group having 1-3 carbon atoms, R⁸ denotes an alkylgroup having 1-3 carbon atoms and R⁹ denotes hydrogen atom, an alkylgroup having 1-3 carbon atoms or a group represented by—(CH₂)n-CR¹⁰═C(R¹¹)R¹² in which n is an integer of 1 to 5, R¹⁰ and R¹¹represent each, independently of each other, hydrogen atom or an alkylgroup having 1-3 carbon atoms and R¹² represents an alkyl group having1-3 carbon atoms, with the proviso that R⁹ is hydrogen atom or an alkylgroup having 1-3 carbon atoms when both p and q are
 1. 16. The randomcopolymer as claimed in claim 10, wherein the non-conjugated linearpolyene (A3) is represented by the formula (2-1) given below:

in which p and q is zero or 1 with the proviso that p and q are not zerosimultaneously, f is an integer of zero to 5 with the proviso that f isnot zero when both p and q are 1, g is an integer of 1 to 6, R¹, R², R³,R⁴, R⁵, R⁶ and R⁷ denote each, independently of each other, hydrogenatom or an alkyl group having 1-3 carbon atoms, R⁸ denotes an alkylgroup having 1-3 carbon atoms and R⁹ denotes hydrogen atom, an alkylgroup having 1-3 carbon atoms or a group represented by—(CH₂)n-CR¹⁰═C(R¹¹)R¹² in which n is an integer of 1 to 5, R¹⁰ and R¹¹represent each, independently of each other, hydrogen atom or an alkylgroup having 1-3 carbon atoms and R¹² represents an alkyl group having1-3 carbon atoms, with the proviso that R⁹ is hydrogen atom or an alkylgroup having 1-3 carbon atoms when both p and q are
 1. 17. The randomcopolymer as claimed in claim 12, wherein the non-conjugated linearpolyene (A3) is represented by the formula (2-1) given below:

in which p and q is zero or 1 with the proviso that p and q are not zerosimultaneously, f is an integer of zero to 5 with the proviso that f isnot zero when both p and q are 1, g is an integer of 1 to 6, R¹, R², R³,R⁴, R⁵, R⁶ and R⁷ denote each, independently of each other, hydrogenatom or an alkyl group having 1-3 carbon atoms, R⁸ denotes an alkylgroup having 1-3 carbon atoms and R⁹ denotes hydrogen atom, an alkylgroup having 1-3 carbon atoms or a group represented by—(CH₂)n-CR¹⁰═C(R¹¹)R¹² in which n is an integer of 1 to 5, R¹⁰ and R¹¹represent each, independently of each other, hydrogen atom or an alkylgroup having 1-3 carbon atoms and R¹² represents an alkyl group having1-3 carbon atoms, with the proviso that R⁹ is hydrogen atom or an alkylgroup having 1-3 carbon atoms when both p and q are
 1. 18. The randomcopolymer as claimed in claim 14, wherein the non-conjugated linearpolyene (A3) is represented by the formula (2-1) given below:

in which p and q is zero or 1 with the proviso that p and q are not zerosimultaneously, f is an integer of zero to 5 with the proviso that f isnot zero when both p and q are 1, g is an integer of 1 to 6, R¹, R², R³,R⁴, R⁵, R⁶ and R⁷ denote each, independently of each other, hydrogenatom or an alkyl group having 1-3 carbon atoms, R⁸ denotes an alkylgroup having 1-3 carbon atoms and R⁹ denotes hydrogen atom, an alkylgroup having 1-3 carbon atoms or a group represented by—(CH₂)n-CR¹⁰═C(R¹¹)R¹² in which n is an integer of 1 to 5, R¹⁰ and R¹¹represent each, independently of each other, hydrogen atom or an alkylgroup having 1-3 carbon atoms and R¹² represents an alkyl group having1-3 carbon atoms, with the proviso that R⁹ is hydrogen atom or an alkylgroup having 1-3 carbon atoms when both p and q are
 1. 19. The rubbercomposition as claimed in claim 5, wherein the non-conjugated cyclicpolyene (A2) is that represented by the formula (1-1) given below:

in which m is an integer of 0 to 2, R¹ to R⁴ denote each, independentlyof each other, an atom or a residue selected from the group consistingof hydrogen atom, halogen atoms and hydrocarbon residues which may havedouble bond, wherein R¹ to R⁴ may be fused together to form a mono- orpolycyclic ring which may have double bond or wherein an alkylideneradical may be formed from the pair of R¹ and R² or R³ and R⁴ or,further, R¹ and R³ or R² and R⁴ may be fused together so as to form adouble bond, with the proviso that at least one of R¹ to R⁴ stands foran unsaturated hydrocarbon residue having at least one double bond, incase the mono- or polycyclic ring formed from R¹ to R⁴ by being fusedtogether has no double bond, in case the pair of R¹ and R² or R³ and R⁴does not form an alkylidene radical and in case R¹ and R³ or R² and R⁴are not fused together to form an endocyclic double bond.
 20. The rubbercomposition as claimed in claim 6, wherein the non-conjugated cyclicpolyene (A2) is that represented by the formula (1-1) given below:

in which m is an integer of 0 to 2, R¹ to R⁴ denote each, independentlyof each other, an atom or a residue selected from the group consistingof hydrogen atom, halogen atoms and hydrocarbon residues which may havedouble bond, wherein R¹ to R⁴ may be fused together to form a mono orpolycyclic ring which may have double bond or wherein an alkylideneradical may be formed from the pair of R¹ and R² or R³ and R⁴ or,further, R¹ and R³ or R² and R⁴ may be fused together so as to form adouble bond, with the proviso that at least one of R¹ to R⁴ stands foran unsaturated hydrocarbon residue having at least one double bond, incase the mono- or polycyclic ring formed from R¹ to R⁴ by being fusedtogether has no double bond, in case the pair of R¹ and R² or R³ and R⁴does not form an alkylidene radical and in case R¹ and R³ or R² and R⁴are not fused together to form an endocyclic double bond.
 21. The rubbercomposition as claimed in claim 19, wherein the structural unit(s)originated from one or more α-olefins (A1) in the random copolymer basedon non-conjugated cyclic polyene comprise at least a structural unitoriginated from ethylene, wherein the mole ratio of (the structural unitoriginated from ethylene) versus (the structural unit(s) originated fromother α-olefin(s) having 3 or more carbon atoms) is in the range of from100/0 to 1/99.
 22. The rubber composition as claimed in claim 20,wherein the structural unit(s) originated from one or more α-olefins(A1) in the random copolymer based on non-conjugated cyclic polyenecomprise at least a structural unit originated from ethylene, whereinthe mole ratio of (the structural unit originated from ethylene) versus(the structural unit(s) originated from other α-olefin(s) having 3 ormore carbon atoms) is in the range of from 100/0 to 1/99.
 23. The rubbercomposition as claimed in claim 19, wherein the structural unit(s)originated from one or more α-olefins (A1) in the random copolymer basedon non-conjugated cyclic polyene comprise at least a structural unitoriginated from ethylene, wherein the mole ratio of (the structural unitoriginated from ethylene) versus (the structural unit(s) originated fromother α-olefin(s) having 3 or more carbon atoms) is in the range of from100/0 to 50/50.
 24. The rubber composition as claimed in claim 20,wherein the structural unit(s) originated from one or more α-olefins(A1) in the random copolymer based on non-conjugated cyclic polyenecomprise at least a structural unit originated from ethylene, whereinthe mole ratio of (the structural unit originated from ethylene) versus(the structural unit(s) originated from other α-olefin(s) having 3 ormore carbon atoms) is in the range of from 100/0 to 50/50.
 25. Therubber composition as claimed in claim 6, wherein the non-conjugatedlinear polyene (A3) is represented by the formula (2-1) given below:

in which p and q is zero or 1 with the proviso that p and q are not zerosimultaneously, f is an integer of zero to 5 with the proviso that f isnot zero when both p and q are 1, g is an integer of 1, to 6, R¹, R²,R³, R⁴, R⁵, R⁶ and R⁷ denote each, independently of each the hydrogenatom or an alkyl group having 1-3 carbon atoms, R⁸ denotes an alkylgroup having 1-3 carbon atoms and R⁹ denotes hydrogen atom, an alkylgroup having 1-3 carbon atoms or a group represented by—(CH₂)n-CR¹⁰═C(R¹¹)R¹² in which n is an integer of 1 to 5, R¹⁰ and R¹¹represent each, independently of each other, hydrogen atom or an alkylgroup having 1-3 carbon atoms and R¹² represents an alkyl group having1-3 carbon atoms, with the proviso that R⁹ is hydrogen atom or an alkylgroup having 1-3 carbon atoms when both p and q are
 1. 26. The rubbercomposition as claimed in claim 20, wherein the non-conjugated linearpolyene (A3) is represented by the formula (2-1) given below:

in which p and q is zero or 1 with the proviso that p and q are not zerosimultaneously, f is an integer of zero to 5 with the proviso that f isnot zero when both p and q are 1, g is an integer of 1 to 6, R¹, R², R³,R⁴, R⁵, R⁶ and R⁷ denote each, independently of each hydrogen atom or analkyl group having 1-3 carbon atoms, R⁸ denotes an alkyl group having1-3 carbon atoms and R⁹ denotes hydrogen atom, an alkyl group having 1-3carbon atoms or a group represented by —(CH₂)n-CR¹⁰═C(R¹¹)R¹² in which nis an integer of 1 to 5, R¹⁰ and R¹¹ represent each, independently ofeach other, hydrogen atom or an alkyl group having 1-3 carbon atoms andR¹² represents an alkyl group having 1-3 carbon atoms, with the provisothat R⁹ is hydrogen atom or an alkyl group having 1-3 carbon atoms whenboth p and q are
 1. 27. The rubber composition as claimed in claim 22,wherein the non-conjugated linear polyene (A3) is represented by theformula (2-1) given below:

in which p and q is zero or 1 with the proviso that p and q are not zerosimultaneously, f is an integer of zero to 5 with the proviso that f isnot zero when both p and q are 1, g is an integer of 1 to 6, R¹, R², R³,R⁴, R⁵, R⁶ and R⁷ denote each, independently of each other, hydrogenatom or an alkyl group having 1-3 carbon atoms, R¹ denotes an alkylgroup having 1-3 carbon atoms and R⁹ denotes hydrogen atom, an alkylgroup having 1-3 carbon atoms or a group represented by—(CH₂)n-CR¹⁰═C(R¹¹)R¹² in which n is an integer of 1 to 5, R¹⁰ and R¹¹represent each, independently of each other, hydrogen atom or an alkylgroup having 1-3 carbon atoms and R¹² represents an alkyl group having1-3 carbon atoms, with the proviso that R⁹ is hydrogen atom or an alkylgroup having 1-3 carbon atoms when both p and q are
 1. 28. The rubbercomposition as claimed in claim 24, wherein the non-conjugated linearpolyene (A3) is represented by the formula (2-1) given below:

in which p and q is zero or 1 with the proviso that p and q are not zerosimultaneously, f is an integer of zero to 5 with the proviso that f isnot zero when both p and q are 1, g is an integer of 1 to 6, R¹, R², R³,R⁴, R⁵, R⁶ and R⁷ denote each, independently of each other hydrogen atomor an alkyl group having 1-3 carbon atoms, R⁸ denotes an alkyl grouphaving 1-3 carbon atoms and R⁹ denotes hydrogen atom, an alkyl grouphaving 1-3 carbon atoms or a group represented by —(CH₂)n-CR¹⁰═C(R¹¹)R¹²in which n is an integer of 1 to 5, R¹⁰ and R¹¹ represent each,independently of each other, hydrogen atom or an alkyl group having 1-3carbon atoms and R¹² represents an alkyl group having 1-3 carbon atoms,with the proviso that R⁹ is hydrogen atom or an alkyl group having 1-3carbon atoms when both p and q are
 1. 29. A rubber material for tires,comprising the random copolymer based on non-conjugated cyclic polyeneas claimed in any one of claim 1, 2, 9, 10 or
 15. 30. A rubber materialfor tires, comprising the rubber composition as claimed in any one ofclaim 5, 6, 19, 20 or
 25. 31. A tire tread produced from the rubbermaterial for tires as claimed in claim
 29. 32. A tire tread producedfrom the rubber material for tires as claimed in claim
 30. 33. A tirewhich has a tire tread as claimed in claim
 31. 34. A tire which has atire tread as claimed in claim 32.